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M\ -G 1916 



JOURNAL 

OF THE 

ASSOCIATION OF OFFICIAL 
AGRICULTURAL CHEMISTS 



Vol. I FEBRUARY 15, 1916 No. 4 






BOARD OF EDITORS 
C. L. Alsberq, Chairman 
R. E. DooiiiTTLE J. P. Street 

E. F. Ladd L. L. Van Sltke 

PART II 

Report of Committee on Editing Methods of An^sis 
Fertilizers 
Soils 

Inorganic Plant Constituents 
Waters 
Tanning Materials 




PUBLISHED QUARTERLY BY 

THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS 

WILLIAMS & WILKINS COMPANY 

BALTIMORE, U. S. A. 

THE CAMBRIDGE UNIVERSITY PRESS 
FETTER LANE, LONDON, E. C. 



Bnt«red «s second-class matter August 25, 1915, at the Post-Office at Baltimore, Maryland, under the Act of Ausust 24, 1912 
Copyright 1916 by Association of Official Aericultural Chemiata 



REPORT 



OF THE 



COMMITTEE ON EDITING TENTATIVE 
AND OFFICIAL 

Methods of Analysis 



THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS 

WILLIAMS & WILKINS COMPANY 

BALTIMORE, U. S. A. 

1916 



^^'m 

•%<^ 



COPYHIGHT, 1916 
BT 

The Association of Opficial Agricctltdrax, Chemists 



COMPOSED AND PRINTED AT TH I 

WAVERLY PRESS 

Br THE Williams & Wilkins Co^:^• \mt 

Baltimore, Md., U. S. A. 



ft 






CONTENTS 

I. Fertilizers ^ 

II. Soils 17 

III. Plant Constituents 29 

IV. Waters 35 

V. Tanning Materials ^^ 

VI. Leathers 59 

VII. Insecticides and Fungicides 63 

VIII. Foods and Feeding Stuffs 79 

IX. Saccharine Products 121 

X. Food Preservatives 141 

XI. Coloring Matters in Foods 155 

XII. Metals in Foods 171 

XIII. Fruits and Fruit Products 177 

XIV. Canned Vegetables 185 

XV. Cereal Foods 187 

XVI. Wines 193 

XVII. Distilled Liquors 243 

XVIII. Beers 249 

XIX. Vinegars 253 

XX. Flavoring Extracts 259 

XXI. Meat and Meat Products 271 

XXII. Dairy Products 287 

XXIII. Fats and Oils 299 

XXIV. Spices and Other Condiments 317 

XXV. Cacao Products 327 

XXVI. Coffees 331 

XXVII. Tea 335 

XXVIII. Baking Powders and Their Ingredients 339 

XXIX. Drugs 351 

Index 367 



ILLUSTRATIONS 

Figure 1. Combustion tube for the determination of total nitrogen 9 

Figure 2. Parr's apparatus for the determination of carbon dioxid 18 

Figure 3. Modified Marr apparatus for determining carbon dioxid 19 

Figure 4. Metal extractor used for extracting tanning materials 56 

Figure 5. Apparatus for distillation of arsenic chlorid 64 

Figure 6. Apparatus for detection of formic acid 153 

Figure 7. Apparatus for the determination of arsenic 172 

Figure 8. Apparatus for the determination of volatile acids 239 

Figure 9. Apparatus for the Folin ammonia determination 275 

Figure 10. Van Slyke apparatus for the determination of amino nitrogen 282 

Figure 11. Details of the deaminizing bulb and connection 283 

Figure 12. Apparatus for the melting point determination 303 

Figure 13. Apparatus for the determination of the Polenske number 309 

Figure 14. Knorr's apparatus for the determination of carbon dioxid 339 

Figure 15. Heidenhain's apparatus for the determination of carbon dioxid 341 



TABLES 

Table 1. Munson and Walker's Table. For calculating dextrose, invert sugar 
alone, invert sugar in the presence of sucrose (0.4 gram and 2 grams 
total sugar), lactose (two forms), and maltose (anhydrous and 

crystallized) 88 

Table 2. Herzfeld's Table. For the determination of invert sugar in mate- 
rials containing 1.5%, or less, of invert sugar and 98.5%, or more, 

of sucrose 99 

Table 3. Meissl and Killer's factors for determinations in materials in which, 
of the total sugars present, 1.5%, or more, is invert sugar, and 98.5%, 

or less, is sucrose 100 

Table 4. Meissl's Table. For the determination of invert sugar alone 101 

Table 5. For the determination of maltose 103 

Table 6. For the determination of lactose 105 

Table 7. Allihn's Table. For the determination of dextrose 107 

Table 8. Krober's Table. For determining pentoses and pentosans 112 

Table 9. For correction of the readings of the Brix spindle when made at other 

than the standard temperature, 17.5°C 123 

17 5°C 
Table 10. For the comparison of specific gravities at ^^ go " . degrees Brix and 

degrees Baume 124 

Table 11. Densities of solutions of cane sugar at 20°C 125 

Table 12. Geerlig's Table. For dry substance in sugar-house products by the 

Abbe refractometer, at 28°C 127 

Table 13. Corrections for temperature 128 

Table 14. Color reactions produced on dyed fibers by various reagents 161 

Table 15. Behavior of certain natural coloring matters with common reagents.. 166 
Table 16. Alcohol Table. For calculating the percentages of alcohol in mix- 
tures of ethyl alcohol and water from their specific gravities 194 

Table 17. Alcohol Table. For calculating the percentages of alcohol in mix- 
tures of ethyl alcohol and water from their Zeiss immersion refrac- 
tometer readings at 17.5°-25°C 208 

Table 18. Scale readings of the Zeiss immersion refractometer at 20°C., corre- 
sponding to each per cent by weight of methyl and ethyl alcohols. . 247 
Table 19. Volimies of milk corresponding to a lactose double normal weight . . . 288 
Table 20. Butyro-refractometer readings and indices of refraction 301 



©C!.SJi6C040 

REPORT OF THE COMMITTEE ON EDITING METHODS 

OF ANALYSIS. 

Washington, D. C, November 16, 1915. 

To The President and Members of the Association of Official Agricul- 
tural Chemists. 
Gentlemen: — Your committee on editing methods of analysis begs leave to report 
that it has completed the work assigned and herewith submits for your consideration 
the revised methods. The committee has included all authorized changes and addi- 
tions, has eliminated obsolete methods in so far as possible, rewritten the text where 
parts appeared obscure, and made such consolidations of general methods and 
rearrangements as in its opinion would promote brevity and clearness. 

In order that the members of the Association may have an opportunity to criti- 
cize the revised methods it is suggested by your committee that this report be 
published in the Journal of the Association with a view to final adoption of the 
methods in 191G. 

Respectfully submitted, 

Committee on Editing Methods of Analysis. 
R. E. Doolittle, Chairman, A. F. Seeker, 
W. A. Withers, G. W. Hoover, 

J. P. Street, B. L. Hartwell. 

Editorial Note: — The Board of Editors submits the following comment upon the 
report of the Committee on Editing Methods of Analysis: 

Inasmuch as the methods of analysis as prescribed by this Association have been 
adopted, by regulation, for the enforcement of the Federal Food and Drugs Act 
and, by law, in many of the States for the enforcement of State laws, certain safe- 
guards to protect their integrity are provided by the Association's Constitution 
and By-Laws. 

The Constitution and By-Laws provide for Official and Provisional Methods 
only. At the last meeting of the Association it was suggested that the "Provisional" 
methods be designated as '"Tentative" and the committee was instructed at the 
afternoon session, Wednesday, November 17, 1915, to make their report accordingly. 
The phraseology of the Constitution was not changed, however, but was referred 
to a committee to be reported upon at the 1916 meeting. Therefore, in the present 
report the word "Tentative" has been substituted for the word "Provisional", 
though the term "Provisional" must be formally retained until the Constitution 
shall have been changed. 

Changes in methods cannot be made until an opportunity has been given members 
of the Association to test them. Before a method can be adopted as Official, it 
must have been tested through cooperative work and must have been recommended 
by the appropriate referee for at least two years. Olficial Methods, therefore, 
are those which have been thoroughly tested and which, in the opinion of the Associa- 
tion, yield accurate results in the hands of its members. In other words, they are 
believed to render as absolutely correct results as are possible in the existing state 
of knowledge concerning the determination in question. Provisional Methods 
are those which, v/hile in the opinion of the Association yielding dependable results 
for comparison, have not as yet been tested so thoroughly as those that have been 
adopted officially. They are believed to be the best of the kind which have been 
tested by the Association but which for reasons stated have not the standing of 
Official Methods. 

The methods in the form last promulgated by the Association, either in Bulletin 
107 (Revised) or as published in their Proceedings of the last eight years, are as 
yet the only enes adopted by the Association. 

It should be clearlj^ understood that the revised methods as published herewith 
are simply the report of the Committee on Editing Methods of Analysis, including 
the recommendations adopted at the 1915 meeting, and at the present time have not 
been officially adopted. The methods are printed at this time to enable the mem- 
bers of the Association to study and criticize them so that they may be able to vote 
on them intelligently at the 1916 meeting at which time the matter will come up 
for final action. 



RECOMMENDATIONS FOR OFFICIAL AND TENTATIVE 
METHODS OF ANALYSIS, AS PRESENTED AT 
THE ANNUAL MEETING OF THE ASSO- 
CIATION OF OFFICIAL AGRICUL- 
TURAL CHEMISTS, NOVEMBER 
16 AND 17, 1915. 

I. FERTILIZERS. 

GENERAL METHODS. 

1 MECHANICAL ANALYSIS OF BONE AND TANKAGE.— TENTATIVE. 

Transfer 100 grams of the original material to a sieve having circular openings 
1/50 inch (0.5 mm.) in diameter. Sift, breaking the lumps by means of a soft rubber 
pestle if the material has a tendency to cake. Weigh the coarse portion remaining 
on the sieve. Determine the fine portion by difference. 

2 PREPARATION OF SAMPLE.— OFFICIAL. 

Reduce the gross sample by quartering to an amount sufficient for analytical 
purposes. Transfer to a sieve having circular openings 1/25 inch (1 mm.) in diameter, 
sift, breaking the lumps with a soft rubber pestle. Grind in a mortar the part re- 
maining on the sieve until the particles will pass through. Mix thoroughly and 
preserve in tightly stoppered bottles. Grind and sift as rapidly as possible to 
avoid loss or gain of moisture during the operation. 

3 MOISTURE.— OFFICIAL. 

Heat 2 grams of the sample prepared as in 2 for 5 hours in a water oven at the 
temperature of boiling water. In the case of potash salts, sodium nitrate, and 
ammonium sulphate heat at about 130°C. to constant weight. The loss in weight 
is considered as moisture. 

TOTAL PHOSPHORIC ACID. 

Gravimetric Method. — Official. 

4 REAGENTS. 

(a) Molybdate solution. — Dissolve 100 grams of molybdic acid in dilute ammo- 
nium hydroxid (144 cc. of ammonium hydroxid (sp. gr. 0.90) and 271 cc. of water) ; 
pour this solution slowly and with constant stirring into dilute nitric acid (489 cc. of 
nitric acid (sp. gr. 1.42) and 1148 cc. of water). Keep the mixture in a warm place 
for several days or until a portion heated to 40°C. deposits no yellow precipitate 
of ammonium phosphomolybdate. Decant the solution from any sediment and 
preserve in glass-stoppered vessels. 

(b) Ammonium nitrate solution.'— Dissolve. 200 grams of commercial ammonium 
nitrate, phosphate free, in water and dilute to 2 liters. 

(C) Magnesia mixture. — Dissolve 22 grams of recently ignited calcined magnesia 
in dilute hydrochloric acid, avoiding an excess of the latter. Add a little calcined 
magnesia in excess, and boil a few minutes to precipitate iron, aluminium, and phos- 

1 



2 METHODS OF ANALYSIS [Chap. 

phoric acid; filter; add 280 grams of ammonium chlorid, 261 cc. of ammonium hydrox- 
id (sp. gr. 0.90) and dilute to 2 liters. Instead of the solution of 22 grams of cal- 
cined magnesia, 110 grams of crystallized magnesium chlorid (MgChOHaO) dissolved 
in water may be used, then add 280 grams of ammonium chlorid and proceed as above. 

(d) Dilute ammonium hydroxid for washing. — Dilute 100 cc. of ammonium hy- 
droxid (sp. gr. 0.90) to 1 liter. 

(e) Magnesium nitrate solution. — Dissolve 320 grams of calcined magnesia in 
nitric acid, avoiding an excess of the latter; then add a little calcined magnesia in 
excess, boil, filter from the excess of magnesia, ferric oxid, etc., and dilute to 2 liters. 

5 PREPAJIATION OF SOLUTION. 

Treat 2 or 2.5 grams of the sample by one of the methods given below: 

(a) Ignite, and dissolve in hydrochloric acid. 

(b) Evaporate with 5 cc. of magnesium nitrate, ignite, and dissolve in hydro- 
chloric acid. 

(C) Boil with 20-30 cc. of strong sulphuric acid in a Kjeldahl flask, adding 2-4 
grams of sodium or potassium nitrate at the beginning of the digestion and a small 
quantity after the solution has become nearly colorless, or adding the nitrate in 
small portions from time to time. After the solution is colorless add 150 cc. of water, 
and boil for a few minutes. 

(d) Digest in a Kjeldahl flask with strong sulphuric acid and such other re- 
agents as are used in either the plain or modified Kjeldahl or Gunning method for 
estimating nitrogen. Do not add any potassium permanganate, but after the 
solution has become colorless add about 100 cc. of water and boil for a few minutes. 

(e) Dissolve in 30 cc. of concentrated nitric acid and a small quantity of hydro- 
chloric acid and boil until organic matter is destroyed. 

(f) Add 30 cc. of concentrated hydrochloric acid, heat and add cautiously, in 
small quantities at a time, about 0.5 gram of finely pulverized potassium chlorate 
to destroy organic matter. 

(g) Dissolve in 15-30 cc. of strong hydrochloric acid and 3-10 cc. of nitric acid. 
This method is recommended for fertilizers containing much iron or aluminium 
phosphate. 

After solution, cool, dilute to 200 cc. or to 250 cc. if a 2.5 gram sample was used. 
Mix, and pour on a dry filter. 

6 DETERMINATION. 

Take an aliquot of the solution prepared as directed above, corresponding to 0.25 
gram, 0.50 gram, or 1 gram, neutralize with ammonium hydroxid, and clear with a 
few drops of nitric acid. In case hydrochloric or sulphuric acid has been used as 
a solvent, add about 15 grams of dry ammonium nitrate or a solution containing 
that amount. To the hot solution add 60-80 cc. of the molybdate solution for every 
decigram of phosphoric acid (PjOb) that is present. Digest at about 65°C. for an 
hour, and determine if the phosphoric acid has been completely precipitated by 
the addition of more molybdate solution to the clear supernatant liquid. Fil- 
ter and wash with cold water or, preferably, ammonium nitrate solution. Dissolve 
the precipitate on the filter with ammonium hj'droxid and hot water and wash 
into a beaker to a bulk of not more than 100 cc. Nearly neutralize with hj'drochloric 
acid, cool, and add magnesia mixture from a burette; add slowly (about 1 drop per 
second), stirring vigorously. After 15 minutes add 12 cc. of ammonium hydroxid 
(sp. gr. 0.90). Let stand till the supernatant liquid is clear (2 hours is usually 
enough) filter, wash with the dilute ammonium hydroxid until the washings are 



I] FERTILIZERS 3 

practically free from chlorin, dry the filter and precipitate and transfer the latter 
to a weighed porcelain crucible. Ignite the filter separately and add its ash to the 
precipitate in the crucible. Ignite to whiteness or to a grayish white, weigh, and 
calculate to phosphoric acid (P2O6). 

Volumetric Method. — OJJicial. 

7 REAGENTS. 

(a) Molybdate solution. — -To 100 cc. of molybdate solution prepared as directed 
in 4 (a), add 5 cc. of nitric acid (sp. gr. 1.42). This solution should be filtered im- 
mediately before using. 

(b) Standard sodium or potassium hydroxid solution. — Dilute 323.81 cc. of N/1 
alkali, free from carbonates, to 1 liter. 100 cc. of the solution should neutralize 
32.38 cc. of N/1 acid; 1 cc. is equivalent to 1 mg. of P2O5 (1% of P2O5 on a basis of 
0.1 gram of substance). 

(C) Standard acid solution. — Prepare an acid solution corresponding to the, 
or to one-half of the, strength of (b), and standardize by titration against that 
solution, using phenolphthalein as indicator. Hydrochloric or nitric acid may be 
used. 

(d) Phenolphthalein solution. — Dissolve 1 gram of phenolphthalein in 100 cc. of 
alcohol. 

8 PREPARATION OP SOLUTION. 

Dissolve according to 5 (b), (6), (f), or (g), preferably by (e), when these acids 
are a suitable solvent, and dilute to 200 cc. with water. 

9 DETERMINATION. 

(a) For percentages of 5 or below use an aliquot corresponding to 0.4 gram of 
substance, for percentages between 5 and 20 use an aliquot corresponding to 0.2 
gram of substance, and for percentages above 20 use an aliquot corresponding to 
0.1 gram of substance. Add 5-10 cc. of nitric acid, depending on the method of 
solution (or the equivalent in ammonium nitrate), nearly neutralize with ammonium 
hydroxid, dilute to 75-100 cc, heat in a water bath to 60°-65°C., and for percentages 
below 5 add 20-25 cc. of freshly filtered molybdate solution. For percentages be- 
tween 5 and 20 add 39-35 cc. of molybdate solution. For percentages greater than 
20 add sufficient molybdate solution to insure complete precipitation. Stir, let 
stand in the bath about 15 minutes, filter at once, wash once or twice with water by 
decantation, using 25-30 cc. each time, agitate the precipitate thoroughly and 
allow to settle; transfer to the filter and wash with cold water until the filtrate from 
2 fillings of the filter yields a pink color upon the addition of phenolphthalein and 1 
drop of the standard alkali. Transfer the precipitate and filter to a beaker or pre- 
cipitating vessel, dissolve the precipitate in a small excess of the standard alkali, 
add a few drops of phenolphthalein solution, and titrate with the standard acid. 

(b) Proceed asin (a) with this exception: Heat in a water bath at 45°-50°C., 
add the molybdate solution, and allow to remain in the bath with occasional stirring 
for 30 minutes. 

(C) Proceed as in (a) to the point where the solution is ready to place in the 
water bath. Then cool the solution to room temperature, add molybdate solution 
at the rate of 75 cc. for each decigram of phosphoric acid present, place the stoppered 
flask containing the solution in a shaking apparatus and shake for 30 minutes at 
room temperature, filter at once, wash, and titrate as in (a). 



4 METHODS OF ANALYSIS [Chap. 

WATER-SOLUBLE PHOSPHORIC ACID. 

1 Gravimetric Method. — Official. 

Place 2 grams of the sample on a 9 cm. filter, wash with successive small portions 
of water, allowing each portion to pass through before adding more, until the filtrate 
measures about 250 cc. If the filtrate is turbid, add a little nitric acid. Make up 
to any convenient volume, mix well, use an aliquot, and proceed as under 6. 

11 Volumetric Method. — Official. 

Treat the sample as directed under 10. To an aliquot of the solution cor- 
responding to 0.2 or 0.4 gram, add 10 cc. of concentrated nitric acid and ammonium 
hydroxid until a slight permanent precipitate is formed, dilute to 60 cc, and pro- 
ceed as directed under 9. 

CITRATE-INSOLUBLE PHOSPHORIC ACID.— OFFICIAL. 

12 REAGENTS. 

In addition to the reagents given under 4 and 7 prepare ammonium citrate solu- 
tion by one of the following methods: 

Ammonium citrate solution. — (1) Dissolve 370 grams of commercial citric acid 
in 1500 cc. of water; nearly neutralize with commercial ammonium hydroxid; cool; 
add ammonium hydroxid until exactly neutral (testing with litmus or azolitmin 
paper), and dilute sufficiently to make the specific gravity 1.09 at 20°C. The vol- 
ume will be about 2 liters; or, 

(2) To 370 grams of commercial citric acid add commercial ammonium hydroxid 
until nearly neutral; reduce the specific gravity to slightly more than 1.09 at 20°C. 
and make exactly neutral, testing as follows: Prepare a solution of fused calcium 
chlorid, 200 grams to the liter, and add 4 volumes of strong alcohol. Make this 
solution exactly neutral, using a small amount of freshly prepared corallin solution 
as preliminary indicator, and test finally by withdrawing a portion, diluting with 
an equal volume of water, and testing with cochineal solution; 50 cc. of this solution 
will precipitate the citric acid from 10 cc. of the citrate solution. To 10 cc. of the 
nearly neutral citrate solution add 50 cc. of the alcoholic calcium chlorid solution, 
stir well, filter at once through a folded filter, dilute with an equal volume of 
water, and test the reaction with neutral solution of cochineal. If acid or alkaline, 
add ammonium hydroxid or citric acid, as the case may be, to the citrate solution, 
mix, and test again, as before. Repeat this process until a neutral reaction is 
obtained. Add sufficient water to make the specific gravity 1.09 at 20°C. 



13 



DETERMINATION. 



(a) Acidulated samples. — Heat 100 cc. of strictly neutral ammonium citrate 
solution (sp. gr. 1.09) to 65°C. in a 250 cc. Erlenmej^er flask placed in a warm water 
bath, keeping the flask loosely stoppered to prevent evaporation. The level of the 
water in the bath should be above that of the citrate solution in the flask. When 
the citrate solution has reached 65°C., drop into it the filter containing the washed 
residue from the water-soluble phosphoric acid solution in 1 0, close tightly with 
a smooth rubber stopper, and shake violently until the filter paper is reduced to 
a pulp, relieving the pressure by momentarily removing the stopper. Place the 
flask in the bath and maintain its contents at exactly 65°C. Shake the flask every 
5 minutes. At the expiration of exactly 30 minutes from the time the filter and the 
residue are introduced, remove the flask from the bath and immediately filter the 
contents as rapidly as possible through a quick-acting filter paper. Wash with 



I] FERTILIZERS 5 

water at 65°C. until the volume of the filtrate is about 350 cc, allowing time for 
thorough draining before adding new portions of water. (1) Transfer the filter 
and its contents to a crucible, ignite until all organic matter is destroyed, add 10- 
15 cc. of strong hydrochloric acid, and digest until all phosphate is dissolved; or, 
(2) Return the filter with contents to the digestion flask, add 30-35 cc. of strong 
nitric acid, 5-10 cc. of strong hydrochloric acid, and boil until all phosphate is dis- 
solved. Dilute the solution as prepared in (1) or (2) to 200 cc. If desired, the filter 
and its contents may be treated according to methods 5 (b), (C) or (d). Mix well, 
filter through a dry filter and proceed as directed under 6 or 9. 

(b) Non-acidulated samples. — In case a determination of citrate-insoluble phos- 
phoric acid is required in non-acidulated samples treat 2 grams of the phosphatic 
material without previous washing with water, precisely as in (a), except when the 
substance contains much animal matter (bone, fish, etc.), in which case dissolve 
the residue insoluble in ammonium citrate by any one of the processes described 
under 5 (b), (C) or (d) and determine phosphoric acid as directed in 6 or 9. 

14 CITRATE-SOLUBLE PHOSPHORIC ACID.— OFFICIAL. 

The sum of the water-soluble and citrate-insoluble subtracted from the total 
gives the citrate-soluble phosphoric acid. 

15 DETECTION OF NITRATES.— OFFICIAL. 

Mix 5 grams of the fertilizer with 25 cc. of hot water and filter. To a portion of 
this solution add 2 volumes of concentrated sulphuric acid, free from nitric acid and 
oxids of nitrogen, and allow the mixture to cool. Add cautiously a few drops of a 
concentrated solution of ferrous sulphate so that the fluids do not mix. If nitrates 
are present the junction shows at first a purple, afterwards a brown, color or if only 
a very minute quantity be present, a reddish color. To another portion of the solu- 
tion add 1 cc. of a 1% solution of sodium nitrate and test as before to determine 
whether sufficient sulphuric acid were added in the first test. 

ORGANIC AND AMMONIACAL NITROGEN ONLY. 

Kjeldahl Method. — Official. 

16 REAGENTS. 

For ordinary work N/2 acid is recommended. For work in determining very 
small amounts of nitrogen N/10 acid is recommended. In titrating mineral acids 
against ammonium hydroxid solution use cochineal or methyl red as indicator. 

(a) Standard hydrochloric acid. — Determine the absolute strength as follows: 
Preliminary test. — Place a measured portion of the acid to be standardized in an 
Erlenmeyer flask with excess of calcium carbonate, to neutralize free acid, and a 
few drops of potassium chromate as indicator. By titration with silver nitrate 
solution determine exactly the quantity required to precipitate the chlorin. Final 
determination. — To a measured portion of the acid to be standardized add from the 
burette 1 drop in excess of the required quantity of silver nitrate solution as deter- 
mined by the preceding test. Heat to boiling, protect from the light, and allow to 
stand until the precipitate is granular. Filter on a tared Gooch crucible, previously 
heated to 140°-150°C., wash with hot water, testing the filtrate to prove excess of 
silver nitrate. Dry the silver chlorid at 140°-150°C., cool and weigh. 

(b) Standard sulphuric acid. — Determine the absolute strength of the acid by 
precipitation with barium chlorid solution as follows: Dilute a measured quantity 
of the acid to be standardized to approximately 100 cc, heat to boiling and add drop 



6 METHODS OF ANALYSIS [Chap, 

by drop a 10 % solution of barium chlorid until no further precipitation occurs. 
Continue the boiling for about 5 minutes, allow to stand for 5 hours or longer in a 
warm place, pour the supernatant liquid on a tared Gooch or on an ashless filter, 
treat the precipitate with 25-30 cc. of boiling water, transfer to the filter and wash 
with boiling water until the filtrate is free from chlorin. Dry, ignite over a Bunsen 
burner and weigh as barium sulphate. 

(C) Standard alkali solution. — Accurately determine the strength of this solution 
by titration against the standard acid. N/10 solution is recommended. 

(d) Sulphuric acid.~Sp. gr. 1.84 and free from nitrates and ammonium sulphate. 

(e) Metallic mercury, or mercuric oxid. — Mercuric oxid should be prepared in the 
wet way, but not from mercuric nitrate. 

(f) Copper sulphate. — Crystallized. 

(g) Potassitim permanganate.— Finely pulverized. 

(h) Granulated zinc or pumice stone. — Added to the contents of the distillation 
flask if necessary to prevent bumping. 

(i) Potassium sulphid solution. — Dissolve 40 grams of commercial potassium 
sulphid in 1 liter of water. 

(j) Sodiv,m hydroxid solution. — A saturated solution, free from nitrates. 

(k) Cochineal solution. — Digest, with frequent agitation, 3 grams of pulverized 
cochineal in a mixture of 50 cc. of strong alcohol and 200 cc. of water for 1 or 2 days 
at ordinary temperature, and then filter. 

(1) Methyl red solution. — Dissolve 1 gram of methyl red (dimethyl-amino-azo- 
benzene-ortho-carbonic acid) in 100 cc. of 95% alcohol. 

17 APPARATUS. 

(a) Kjeldahl flasks for both digestion and distillation. — Total capacity of about 
550 cc, made of hard, moderately thick, and well-annealed glass. 

(b) Distillation flasks. — For distillation any suitable flask of about 550 cc. capac- 
ity may be used. It is fitted with a rubber stopper through which passes the lower 
end of a Kjeldahl connecting bulb to prevent sodium hydroxid being carried over 
mechanically during distillation. The bulb should be about 3 cm. in diameter, and 
the tubes should be of the same diameter as the condenser tube with which the upper 
end of the bulb tube is connected by means of rubber tubing. 

1 8 DETERMINATION. 

Place 0.7-3.5 grams, according to the nitrogen content, of the substance to be 
anal.vzed in a digestion flask with approximately 0.7 gram of mercuric oxid, or its 
equivalent in metallic mercury, and add 20-30 cc. of sulphuric acid (0.1-0.3 gram of 
crystallized copper sulphate may also be used in addition to the mercury, or in 
place of it). Place the flask in an inclined position and heat below the boiling 
point of the acid until frothing has ceased. (A small piece of paraffin may be added to 
prevent extreme foaming.) Then raise the heat until the acid boils briskly and digest 
for a time after the mixture is colorless or nearly so, or until oxidation is complete. 
Remove the flask from the flame, hold it upright, and while still hot add care- 
fully potassium permanganate in small quantities at a time until, after shaking, 
the liquid remains green or purple. 

After cooling dilute with about 200 cc. of water, add a few pieces of granulated 
zinc or pumice stone, if necessary to prevent bumping, and 25 cc. of potassium sul- 
phid solution with shaking. Next add sufficient sodium hydroxid solution to make 
the reaction strongly alkaline, 50 cc. are usually enough, pouring it down the side of 
the flask so that it does not mix at once with the acid solution. Connect the flask 



I] FERTILIZERS 7 

with the condenser, mix the contents by shaking, distil until all ammonia has passed 
over into a measured quantity of the standard acid and titrate with the standard 
alkali. The first 150 cc. of the distillate will generally contain all the ammonia. 

The use of mercuric oxid in this operation greatly shortens the time necessary 
for digestion, which is rarely over an hour and a half in case of substances most 
difficult to oxidize, and is more commonly less than an hour. In most instances 
the use of potassium permanganate is quite unnecessary, but it is believed that in 
exceptional cases it is required for complete oxidation, and in view of the uncer- 
tainty it is always used. The potassium sulphid removes all the mercury from the 
solution, and so prevents the formation of mercuro-ammonium compounds which 
are not completely decomposed by the sodium hydroxid. The addition of zinc 
gives rise to an evolution of hydrogen and prevents violent bumping. 

Previous to use the reagents should be tested by a blank experiment with sugar. 
The sugar partially reduces any nitrates present that might otherwise escape notice. 

Gunning Method. — Official. 

19 REAGENTS. 

Potassium sulphate. — Pulverized. 

The other reagents and standard solutions used are described under 16. 

20 APPARATUS. 

The apparatus used is described under 17. 



21 



DETERMINATION. 



Place 0.7-3.5 grams, according to the nitrogen content, of the substance to be 
analyzed in a digestion flask. Add 10 grams of powdered potassium sulphate and 
15-25 cc. (ordinarily about 20 cc.) of sulphuric acid (0.1-0.3 gram of crystallized 
copper sulphate may also be added). Conduct the digestion as in the Kjeldahl 
process, starting with a temperature below the boiling point and increasing the heat 
gradually until frothing ceases. Digest for a time after the mixture is colorless or 
nearly so, or until oxidation is complete. Do not add either potassium permanganate 
or potassium sulphid. Cool, dilute, neutralize, distil, and titrate with the standard 
alkali. In neutralizing before distilling it is convenient to add a few drops of 
phenolphthalein indicator or litmus paper. The pink color given by phenolphthal- 
ein indicating an alkaline reaction is destroyed by a considerable excess of strong 
fixed alkali. 

Kjeldahl-Gunning-Arnold Method. — Official. 

22 REAGENTS AND APPARATUS. 

Described under 16, 17 and 19. 

23 DETERMINATION. 

Place 0.7-3.5 grams, according to the nitrogen content, of the substance to be 
analyzed in a digestion flask. Add 15-18 grams of potassium sulphate, 1 gram of 
copper sulphate, 1 gram of mercuric oxid, or its equivalent in metallic mercury, 
and 25 cc. of sulphuric acid. Heat gently until frothing ceases, then boil the mixture 
briskly, and continue the digestion for a time after the mixture is colorless or nearly 
so or until oxidation is complete. Cool, dilute with about 200 cc. of water, add 50 cc. 
of potassium sulphid solution, make strongly alkaline with sodium hydroxid solu- 
tion and complete the determination as directed under 18. 



8 METHODS OF ANALYSIS [Chap. 

TOTAL NITROGEN. 

Kjeldahl Method Modified to include the Nitrogen of Nitrates. — Official. 

24 REAGENTS. 

(a) Zinc dust. — Impalpable powder. Granulated zinc or zinc filings will not 
answer. 

(b) Sodium thiosulphate. 

(C) Commercial salicylic acid. 

The other reagents and standard solutions are described under 16. 

25 APPARATUS. 

The apparatus used is described under 1 7. 

26 DETERMINATION. 

Place 0.7-3.5 grams, according to the nitrogen content, of the substance to be 
analyzed in a Kjeldahl digestion flask. (1) Add 30 cc. of sulphuric acid containing 

1 gram of salicylic acid, shake until thoroughly mixed, allow to stand for at least 
30 minutes, and then add 5 grams of crystallized sodium thiosulphate and digest as 
directed below; or, (2) Add to the substance 30 cc. of sulphuric acid containing 2 
grams of salicylic acid, allow to stand at least 30 minutes and then add gradually 

2 grams of zinc dust, shaking the contents of the flask at the same time and digest 
as follows: 

Place the flask on the stand for holding the digestion flasks and heat over a low 
flame until all danger from frothing has passed. Then raise the heat until the acid 
boils briskly and continue the boiling until white fumes no longer escape from the 
flask. This requires about 5-10 minutes. Add approximately 0.7 gram of mercuric 
oxid, or its equivalent in metallic mercury, and continue the boiling until the liquid 
in the flask is colorless, or nearly so. In case the contents of the flask are likely to 
become solid before this point is reached, add 10 cc. more of sulphuric acid. Complete 
the oxidation with a little potassium permanganate in the usual way and proceed 
as directed under 18. The reagents should be tested by blank experiments. 

Gunning Method Modified to include the Nitrogen of Nitrates. — Ofiicial. 

27 REAGENTS AND APPARATUS. 

The reagents and standard solutions are described under 16, 17, 19 and 24. 



28 



DETERMINATION. 



Place 0.7-3.5 grams, according to the nitrogen content, of the substance to be 
analyzed in a digestion flask. Add 30-35 cc. of salicylic acid mixture (30 cc. of sul- 
phuric acid to 1 gram of salicylic acid) ; shake until thoroughly mixed, and allow to 
stand for at least 30 minutes with frequent shaking. Add 5 grams of sodium thio- 
sulphate and heat the solution for 5 minutes ; cool ; add 10 grams of potassium sulphate 
and heat very gently until foaming ceases, then strongly until nearly colorless, 
and proceed as directed under 21 . 

Absolute or Cupric Oxid Method. — Ofiicial. 

29 REAGENTS. 

(a) Coarse cupric oxid. — Ignite and cool before using. 

(b) Fine cupric oxid. — Grind (a). 



I] 



FERTILIZERS 



(C) Metallic copper. — Granulated copper, or fine copper gauze, heated and cooled 
in a current of hydrogen or by dropping the heated copper into a test tube containing 
a few cc. of methyl alcohol. 

(d) Sodium bicarbonate. — Free from organic matter. 

(e) Caustic potash solution. — A supersaturated solution of caustic potash in hot 
water. 



30 



APPARATUS. 



(a) Combustion tube. — Hard Bohemian glass, about 65 cm. long, 12.7 mm. internal 
diameter and sealed at one end. 

(b) Azotometer. — Capacity 100 cc, accurately calibrated. 
(C) Sprengel mercury air pump. 

(d) Small paper scoop. — Made from stiff writing paper. 



31 



DETERMINATION. 



Use 1-2 grams of ordinary commercial fertilizers. In the case of highly nitrogen- 
ized substances, the amount to be used is governed by the amount of nitrogen esti- 
mated to be present. Fill the tube (Fig. 1) as follows: (1) about 5 cm. of coarse 



y/. 



n^ 



I 



iS>l»".A^^!■.•^v^^v'.^•■•.^^^»*♦«-.•.^;^,««A•,v.•*U'J«i•''."■.♦*.'.V«^V ***«'' 



.A_ 



S ci^. /o cm. 

COAffSE SUS6TAIVC£ 
ox IV. AND FINE OXID. 



30 cm. 

COARSE OXID. 



^ 



21 



m 



izlUluDB Wl 



r CM. 6CH 
METALLIC coniai 

COPPER. OKIO. 

AseeaTOA 
nue. 



2.S CM. 

FREB e NO- 



SODIUM 
BKARBONATE. 



THE ROMAN NUMERALS REFER TO THE ORDER IN WHICH THE DIFFERENT 
PORTIONS ARE TO BE HEATED. 

FIG. 1. 



cupric oxid; (2) place on the small paper scoop a sufficient amount of the fine cupric 
oxid which, when mixed with the substance to be analyzed, will fill about 10 cm. of 
the tube; pour on this the substance, rinsing the watch glass with a little of the fine 
oxid, and mix thoroughly with a spatula, pour into the tube, rinsing the scoop with 
a little fine oxid; (3) about 30 cm. of coarse cupric oxid; (4) about 7 cm. of metallic 
copper; (5) about 6 cm. of coarse cupric oxid; (6) a small plug of asbestos; (7) 0.8-1 
gram of sodium bicarbonate; (8) a large loose plug of asbestos. 

After the tube is filled hold in a horizontal position and tap gently on the table 
in order that a canal may be formed in the upper portion of the fine cupric oxid. 
Place the tube in the combustion furnace, leave about 2.5 cm. of it projecting and 
connect with the pump by a rubber stopper smeared with glycerol, taking care to 
make the connection perfectly tight. In order to protect the latter from the heat, 
place an asbestos plate, having a circular opening in the center, over the projecting 
end of the tube. 

Exhaust the air from the tube by means of the pump. When a vacuum has been 
obtained, allow the flow of mercury to continue; light the gas under that part of the 



10 METHODS OF ANALYSIS [Chap, 

tube containing the metallic copper, the anterior layer of cupric oxid and the sodium 
bicarbonate. As soon as the vacuum is destroyed and he apparatus filled w th 
carbon dioxid, shut off the flow of mercury and at once introduce the delivery tube 
of the pump into the receiving arm of the azotometer just below the surface of the 
mercury seal so that the escaping bubbles will pass into the air and not into the tube, 
to avoid the useless saturation of the caustic potash solution. 

When the flow of carbon dioxid has very nearly or completely ceased, pass the 
delivery tube down into the receiving arm so that the bubbles will escape into the 
azotometer. Light the gas under the 30 cm. layer of oxid, heat gently for a few 
minutes, to drive out any moisture that may be present, and then bring to a red heat. 
Heat gradually the mixture of substance and oxid, lighting a jet at a time. Avoid 
a too rapid evolution of bubbles, which should be allowed to escape at the rate 
of about one per second or a little faster. When the burners under the mixture have 
all been turned on, light the gas under the layer of oxid at the end of the tube. 
When the evolution of bubbles has ceased, turn out all the burners except those 
under the metallic copper and anterior layer of oxid, and allow to cool for a few min- 
utes. Exhaust with the pump and remove the azotometer before the flow of mercury 
has stopped. Break the connection of the tube with the pump, stop the flow of 
mercury, and extinguish the burners. Allow the azotometer to stand for at least 
an hour, or cool with a stream of M'^ater until the volume and temperature become 
constant. 

Adjust accurately the level of the potassium hydroxid solution in the bulb to 
that in the azotometer; note the volume of the nitrogen, temperature, and height of 
barometer; calculate the weight of the nitrogen as usual. 

AMMONIACAL NITROGEN. 

32 Magnesium Oxid Method. — Official. 

Place 0.7-3.5 grams, according to the ammonia content, of the substance to be 
analyzed in a distillation flask with about 200 cc. of water and 5 grams or more of 
magnesium oxid, free from carbonates. Then connect the flask with a condenser and 
distil 100 cc. of the liquid into a measured quantity of standard acid and titrate 
with standard alkali solution. 

NITRIC AND AMMONIACAL NITROGEN. 

33 Ulsch-Slreet Method.— Official. 

Flace 1 gram of the sample in a half-liter flask, add about 30 cc. of water and 2-3 
grams of reduced iron, and, after standing sufficiently long to insure solution of the 
soluble nitrates and ammonium salts, add 10 cc. of a mixture of strong sulphuric acid 
with an equal volume of water; shake thoroughly, place a long-stemmed funnel in the 
neck of the flask to prevent mechanical loss, and allow to stand for a short time until 
the violence of the reaction has moderated. Heat the solution slowly, boil for 5 
minutes, and cool. Add about 100 cc. of water, a little paraffin, and 7-10 grams of 
magnesium oxid, free or nearly free from carbonates. Connect with a condenser, 
such as is used in the Kjeldahl method, and boil the mixture for 40 minutes, nearly 
to dryness; collect the ammonia in a measured quantity of standard acid, and titrate 
with standard alkali solution in the usual manner. The nitrogen obtained represents 
the nitrates plus the ammonium salts contained in the sample. 

In the analysis of nitrate salts proceed as above, except that 25 cc. of the nitrate 
solution, equivalent to 0.25 gram of the sample, are employed with 5 grams of re- 
duced iron After boiling add 75 cc. of water and an excess of sodium hydroxid 
solution and complete the determination as above. 



I] FERTILIZERS 1 1 

34 Zinc-Iron Method. — Official. 

Dissolve 10 grams of the sample in water and dilute to 500 cc. Place 25 cc. of 
this solution, corresponding to 0.5 gram of the substance, in a 400 cc. distillation flask, 
add 120 cc. of water, 5 grams of well-washed and dried zinc dust, and 5 grams of 
reduced iron. To the solution add 80 cc. of saturated sodium hydroxid solution, 
connect the flask with the condensing apparatus and conduct the distillation simul- 
taneously with the reduction, collecting the ammonia in standard acid. Continue 
the distillation until 100 cc. have been distilled and titrate with standard alkali 
solution. 

NITROGEN IN NITRATE SALTS. 

35 Ferrous Sulphate-Zinc-Soda Method.— Tentative. 

Place 0.5 gram of the nitrate salt in a 600-700 cc. flask, add 200 cc. of water, 
5 grams of powdered zinc, 1-2 grams of ferrous sulphate, and 50 cc. of sodium hy- 
droxid solution (36° Baume). Connect with the distilling apparatus, distil, collect 
the distillate in the usual way in N/10 sulphuric acid and titrate with standard 
alkali solution. 

ORGANIC NITROGEN SOLUBLE IN NEUTRAL PERMANGANATE.— OFFICIAL. 

36 Preliminary Test {Detertnination of Water-Insoluble Organic Nitrogen). 

Place 1 gram of the material on an 11 cm. filter paper and wash with water at 
room temperature until the filtrate measures 250 cc. Dry and determine nitrogen 
in the residue as in 1 8 or 21 , making a correction for the nitrogen of the filter, 
if necessar3\ 

37 DETERMINATION. 

Place a quantity of the fertilizer, equivalent to 50 mg. of water-insoluble organic 
nitrogen as determined in 36, on a moistened 11 cm. filter paper and wash with water 
at room temperature until the filtrate measures 250 cc. Transfer the insoluble 
residue with 25 cc. of tepid water to a 300 cc. Griffin low-form beaker, add 1 gram 
of sodium carbonate, mix, and add 100 cc. of 2% permanganate. Cover with a 
watch glass and immerse for 30 minutes in a steam or hot water bath so that the level 
of the liquid in the beaker is below that of the water in the bath. Stir twice at inter- 
vals of 10 minutes. At the end of the digestion remove from the bath, add immedi- 
ately 100 cc. of cold water, and filter through a heavy 15 cm. folded filter. Wash 
with small quantities of cold water until the filtrate measures about 400 cc. De- 
termine nitrogen in the residue and filter, as in 1 8 or 21 , correcting for the nitrogen 
contained in the latter. The nitrogen thus obtained is the inactive water-insoluble 
organic nitrogen. Subtract this result from that obtained in 36 to obtain the 
percentage of organic nitrogen soluble in neutral permanganate. 

ORGANIC NITROGEN SOLUBLE IN ALKALINE PERMANGANATE.— OFFICIAL. 
(Not applicable to fertilizers containing cottonseed meal or castor pomace.) 

38 PREPARATION OF SAMPLE. 

(a) Mixed fertilizers. — Place an amount of material, equivalent to 50 mg. of water- 
insoluble organic nitrogen determined as directed under 36, on a filter paper and 
wash with water at room temperature until the filtrate measures 250 cc. 



12 METHODS OF ANALYSIS [Chap. 

(b) Raw materials. — Place an amount of material, equivalent to 50 mg. of water- 
insoluble organic nitrogen determined as directed under 36, in a small mortar, add 
about 2 grams of powdered rock phosphate, mix thoroughly, transfer to a filter paper, 
and wash with water at room temperature until the filtrate measures 250 cc. 
When much oil or fat is present, it is well to wash with ether before extracting with 
water. 

39 DETERMINATION. 

Dry the residue of 38 at a temperature not exceeding 80°C. and transfer from the 
filter to a 500-600 cc. Kjeldahl distillation flask. Add 20 cc. of water, 15-20 small 
glass beads, or fragments of pumice stone, a piece of paraffin the size of a pea, and 
100 cc. of alkaline permanganate solution (25 grams of pure potassium permanganate 
and 150 grams of sodium hydroxid, separately dissolved in water, the solutions cooled, 
mixed, and made to a volume of 1 liter). Connect with an upright condenser to 
the lower end of which a receiver containing standard acid has been attached. 
Digest slowly, for at least 30 minutes, below distillation point, with a very low flame, 
using coarse wire gauze and asbestos paper between the flask and flame. Gradually 
raise the temperature and, after any danger from frothing has passed, distil until 
95 cc. of the distillate are obtained, and titrate as usual. When a tendency to froth 
is noticed, lengthen the digestion period and no trouble will be experienced when the 
distillation is begun. During the digestion gently rotate the flask occasionally, 
particularly if the material shows a tendency to adhere to the sides. The nitrogen 
thus obtained is the active water-insoluble organic nitrogen. 

POTASH. 

Method I. 
Lindo-Gladding Method. — Official. 

40 REAGENTS. 

(a) Ammonium chlorid solution. — Dissolve 100 grams of ammonium chlorid in 
500 cc. of water, add 5-10 grams of pulverized potassium-platinic chlorid, and shake 
at intervals for 6-8 hours. Allow the mixture to settle overnight and filter. The 
residue may be used for the preparation of a fresh supply. 

(b) Platinum solution. — A platinic chlorid solution containing the equivalent of 
1 gram of metallic platinum (2.1 grams of HzPtCle) in every 10 cc. 

(C) 80% alcohol. — Sp. gr. 0.86-15 at -f^-. Denatured alcohol, made up according 
to formula 1 (U. S. Internal Rev., Reg. No. 30, Revised, Aug. 22, 1911, p. 45) and di- 
luted with water to make 80% alcohol by volume, may also be used. 



41 



PREPARATION OF SOLUTION. 



(a) Mixed fertilizers. — Place 2.5 grams of the sample upon a 12.5 cm. filter paper 
and wash with boiling water until the filtrate amounts to about 200 cc. Add to the 
filtrate 2 cc. of concentrated hydrochloric acid, heat to boiling, transfer to a 250 cc. 
graduated flask and add to the hot solution a slight excess of ammonium hj^droxid 
and sufficient ammonium oxalate to precipitate all the lime present, cool, dilute to 
250 cc, mix, and pass through a dry filter. 

(b) Potash salts; muriate and sulphate of potash, sulphate of potash and magnesia, 
and kainit. — Dissolve 2.5 grams and dilute to 250 cc. without the addition of am- 
monium hydroxid and ammonium oxalate. 

(C) Organic compounds. — When it is desired to determine the total amount of 
potash in organic substances, such as cottonseed meal, tobacco stems, etc., saturate 



I] FERTILIZERS 13 

10 grams of the sample with strong sulphuric acid and ignite in a muffle at a low red 
heat to destroy organic matter. Add a little strong hydrochloric acid, warm slightly 
in order to loosen the mass from the dish, transfer to a 250 cc. graduated flask, add 
ammonia and ammonium oxalate and proceed as in (a). 



42 



DETERMINATION. 



(a) Mixed fertilizers. — Evaporate 50 cc. of the solution in 41 (a) nearly to dryness, 
add 1 cc. of dilute sulphuric acid (1 to 1), evaporate to dryness, and ignite to white- 
ness. Maintain a full red heat until the residue is perfectly white. Dissolve the 
residue in hot water, using at least 20 cc. for each decigram of potassium oxid pres- 
ent, add a few drops of hydrochloric acid, and platinum solution in excess. Evap- 
orate on a water bath to a thick paste. Treat the residue with 80% alcohol, avoid- 
ing exposure to ammonia. Filter, wash the precipitate thoroughly with 80% alco- 
hol both by decantation and on the filter, continuing the washing after the filtrate 
is colorless. Then wash with 10 cc. of the ammonium chlorid solution to remove 
impurities from the precipitate and repeat 5 or 6 times. Wash again thoroughly 
with 80% alcohol and dry the precipitate for 30 minutes at 100°C. Weigh and cal- 
culate to potassium oxid. The precipitate should be perfectly soluble in water. 

(b) Muriate of potash. — Acidify 50 cc. of the solution prepared according to 41 
(b) with a few drops of hydrochloric acid, add 10 cc. of platinum solution and evapo- 
rate to a thick paste. Treat the residue as under (a). 

(C) Sulphate of potash; sulphate of potash and magnesia; and kainit. — Acidify 
50 cc. of the solution prepared according to 41 (b) with a few drops of hydrochloric 
acid and add 15 cc. of platinum solution. Evaporate the mixture and proceed as 
directed under (a), except that 25 cc. portions of the ammonium chlorid solution 
should be used. 

(d) Water-soluble potash in wood ashes and cotton hull ashes. — Prepare the solution 
according to 41 (a) and proceed as directed under (a), paying special attention to 
the last sentence. 

Method II.— Official. 
(The Lindo-GIadding method is preferable in the presence of soluble sulphates.) 

43 REAGENTS. 

Described under 40. 

44 PREPARATION OF SOLUTION. 

Prepare the solution as directed under 41 , omitting in all cases the addition of 
ammonium hydroxid and ammonium oxalate. 

45 DETERMINATION. 

Dilute 25 cc. of the solution made as directed under 44 (50 cc. if less than 10% 
of potassium oxid be present) to 150 cc, heat to 100°C., and add, drop by drop, with 
constant stirring, a slight excess of barium chlorid solution. Without filtering, add 
in the same manner barium hydroxid solution in slight excess. Filter while hot and 
wash until the precipitate is free from chlorin. Add to the filtrate 1 cc. of strong 
ammonium hydroxid, and then a saturated solution of ammonium carbonate until 
the excess of barium is precipitated. Heat and add, in fine powder, 0.5 gram of 
pure oxalic acid or 0.75 gram of ammonium oxalate. Filter, wash free from chlorin, 
evaporate the filtrate to dryness in a platinum dish, and ignite carefully over the free 



14 METHODS OF ANALYSIS [Chap. 

flame, below a red heat, until all volatile matter is driven off. Digest the residue 
with hot water, filter through a small filter and dilute the filtrate, if necessary, so 
that for each decigram of potassium oxid there will be at least 20 cc. of liquid. Acid- 
ify with a few drops of hydrochloric acid and add platinum solution in excess. Evap- 
orate on a water bath to a thick paste and treat the residue with 80% alcohol, both by 
decantation and after collecting on a Gooch or other form of filter, dry for 30 minutes 
at 100°C. and weigh. If there is an appearance of foreign matter in the double salt, 
it should be washed as in 42 (a) with several portions of 10 cc. each of the 
ammonium chlorid solution. 

THOMAS OR BASIC SLAG.— TENTATIVE. 

48 MECHANICAL ANALYSIS. 

Proceed as directed under 1 , using 10 grams of material. 

47 PREPARATION OF SAMPLE. 
Prepare the sample as directed under 2. 

TOTAL PHOSPHORIC ACID. 

Gravimetric Method. 

48 PREPARATION OF SOLUTION. 

Prepare the solution for analysis as directed under 5 (G), or in strong hydrochloric 
acid alone. In the latter case after the portion for analysis is measured out, add 
nitric acid and heat for a few minutes. 



49 



DETERMINATION. 



Dehydrate an aliquot (20 cc.) of 48 by evaporating to dryness on a steam or hot 
water bath; treat with 5 cc. of hydrochloric acid and 25 cc. of hot water; digest in 
order to complete solution and filter off silica. From this point proceed as directed 
under 6. Before precipitating with magnesia mixture, add 5 cc. of 5% sodium acetate. 

50 Volumetric Method. 

Prepare the solution as directed under 5 (G) and determine the phosphoric acid 
in an aliquot of this solution as directed under 9, standardizing the solutions 
against a standard phosphate material of approximately the same composition 
as the sample under examination. 

CITRATE-SOLUBLE PHOSPHORIC ACID. 

Gravimetric Method. — {Wagner's Method.) 

51 PREPARATION OF SOLUTION. 

Weigh 5 grams of the slag into a 500 cc. Wagner flask containing 5 cc. of 95% 
alcohol. (The flask should have a neck width of at least 22 mm. and should be 
marked at least 8 cm. below the mouth.) Make up to the mark with 2% citric acid 
solution of a temperature of 17.5°C. Fit the flask with a rubber stopper and place 
at once in a rotary apparatus, shaking the flask for 30 minutes at the rate of 30-40 
revolutions per minute, at the end of which time remove the flask, filter immediately 
on a dry filter and analyze the solution at once. 



I] FERTILIZERS 15 

52 DETERMINATION. 

To 50 cc. of the clear filtrate in a beaker add 100 cc. of molybdate solution prepared 
as directed under 4 (a). Place the beaker in a water bath, until the temperature 
of the beaker's contents reaches eS^C, remove from the bath and cool to room tem- 
perature. Filter and wash the yellow precipitate of ammonium phosphomolybdate 
4 or 5 times with 1% nitric acid. Dissolve the precipitate in 100 cc. of cold 2% 
ammonium hydroxid, nearly neutralize with hydrochloric acid and add to the solu- 
tion, drop by drop, with continuous stirring, 15 cc. of magnesia mixture prepared as 
directed under 4 (C) and proceed as under 6. 

53 Volumetric Method. 

In an aliquot of the clear solution prepared as in 51, determine the phosphoric 
acid as directed under 9. 



II. SOILS. 

1 DIRECTIONS FOR TAKING SAMPLES.— OFFICIAL. 

Sampling should be done preferably when the soil is reasonably dry. Remove 
from the surface all vegetable material not incorporated with the soi'. With a soil 
auger or tube, whichever may be better adapted to the soil conditions, take a 
sufficient number of sub-samples at properly distributed points to secure composite 
samples representative of the entire tract. 

(a) Surface soil. — Take a composite sample representative of the entire tract 
to a depth of either (1) 6 inches, (2) the average depth of the plowed soil if this ex- 
ceeds 6 inches, or (3) a maximum depth of 12 inches when there is no clear line of 
demarcation between the soil and sub-soil above this depth. 

(b) Sub-soil.— Take a composite sample of each important and distinctly different 
soil stratum below the surface section already sampled to a total depth of 40 inches. 
If a soil auger is used, before taking sub-soil samples the hole should be enlarged 
and carefully cleaned out with the auger to prevent contamination of the several 
substrata when the sample is being withdrawn. 

Mix each composite sample thoroughly and, after cutting down by quartering to 
about 2-4 pounds, air-dry in a cool, well- ventilated place. 

It is recommended that the weight of a given volume of the soil as it lies in the 
field be taken for calculating the percentage results obtained by analysis to pounds 
per given area of the soil. 

2 PREPARATION OF SAMPLE.— OFFICIAL. 

After air-drying and weighing the sample, pulverize in a porcelain mortar, using 
a rubber-tipped pestle to avoid the reduction of rock fragments, and pass through 
a sieve with circular openings 1/25 inch (1 mm.) in diameter. Discard the detritus 
and weigh. Thoroughly mix the sifted material and preserve in a suitable stoppered 
container. 

For the quantitative determination of any of the constituents, prepare a very 
finely pulverized sub-sample of the sifted material, using an agate mortar. 

3 MOISTURE.— OFFICIAL. 

Dry 2 or more grams of the sample, as prepared under 2, in a tared platinum dish 
for 5 hours at the temperature of boiling water; cover the dish, cool in a desiccator, 
and weigh rapidly to prevent the absorption of moisture. Heat, cool, and weigh 
at intervals of 2 hours to constant weight. The loss of weight is reported as moisture. 

4 VOLATILE MATTER.— OFFICIAL. 

Heat the dish and dry soil from 3 to full redness, stirring occasionally, until all or- 
ganic matter is destroyed. If the soil contains appreciable quantities of carbonates, 
cool and moisten with a few drops of saturated ammonium carbonate solution, dry 
and heat to dull redness to expel ammonium salts; cool in a desiccator and weigh. 

17 



18 
5 



METHODS OF ANALYSIS 

ORGANIC CARBON.— OFFICIAL. 

APPARATUS. 



[Chap. 



(a) A calorimeter bomb. — Use a type that permits the recovery and transfer of the 
entire solid residue of the exploded charge to a small vessel by means of a jet of 
water. 

(b) Parr's apparatus for determining carbon dioxid.^ — Illustrated in Fig. 2. 




FIG. 2. PARR'S APPARATUS FOR THE DETERMINATION OF CARBON DIOXID. 

This consists of a 150 cc. Erlenmeyer flask {F) fitted with a 3-holed stopper through 
2 of which the stems of 2 dropping funnels (5) and {A) extend almost to the bottom 
of the flask. A capillary tube, passing through the third hole and flush with the 
bottom of the stopper, connects with the gas burette {B). 

(C) A simple Hemple gas pipette. — Contains 30% potassium hydroxid solution. 



DETERMINATION. 



6 

Introduce 2 grams of soil as prepared under 2 (1 gram if high in organic matter), 
0.75 gram of magnesium powder, and 10 grams of sodium peroxid, into the closed dry 
calorimeter bomb, and mix thoroughly by shaking the bomb back and forth. Explode 
the charge by means of an electric spark or by dropping a red hot plug into the bomb 
through an automatic valve which closes immediately after the plug enters. Remove 
the residue from the bomb, using as little hot water as possible, heat to boiling, and 
transfer to the receiving funnel (S) of Parr's apparatus. From the acid funnel (A) 
run 50 cc. of sulphuric acid (1 to 2) into the flask (F). Connect the apparatus and 
slowly add the contents from the receiving funnel (S). The carbon dioxid gener- 
ated passes through the capillary tube into the graduated burette (B). Heat the 
contents of the flask (F) to boiling and boil for 1 minute, then force the gases into 
the graduated burette (B) by introducing water into the flask (F) through the fun- 
nel (*S). Read the burette, recording the temperature and pressure. Pass the gas 
into an ordinary absorption pipette containing 30% potassium hydroxid solution. 
Shake the gas with the solution until carbon dioxid is wholly absorbed. Return the 



Ill 



SOILS 



19 



residual gas to the graduated burette (JS), and again read the burette noting the 
temperature and pressure. The difference in readings calculated to standard con- 
ditions of temperature and pressure gives the number of cc. of carbon dioxid derived 
from the total carbon in the sample. Conduct a blank determination upon the 
reagents used. If an appreciable amount of carbon dioxid is obtained in the blank, 
the result expressed in terms of total carbon must be corrected accordingly. 

Determine the inorganic carbon as directed under 9 and subtract it from the total 
carbon to obtain the organic carbon. 



INORGANIC CARBON. 

Modified Marr Method.'^— Tentative. 

7 REAGENTS. 

(a) N /lO hydrochloric acid. 

(b) N /lO sodium hijdroxid. 

(C) Dilute hydrochloric acid. — Dilute 25 cc. of concentrated hydrochloric acid 
(sp. gr. 1.19) to 250 cc. with carbon dioxid-free water. 

(d) Barium hydroxid solution. — Prepare a saturated aqueous solution of barium 
hydroxid, filter through asbestos into a large container through which air free 
from carbon dioxid has been aspirated for some time, and provide an arrangement 
whereby the solution may be delivered by air pressure or gravity and kept from 
contact with carbon dioxid by means of soda lime tubes. 

(e) Carbon dioxid-free water. — Use recently boiled and cooled water, or water 
from which carbon dioxid has been removed by aeration for a sufficient length of 
time with carbon dioxid-free air. Keep in a container provided with a similar 
attachment as in (d). 



8 



APPARATUS. 



HALF FULL OF 

BEADS OR 
BROKEN GLASS 




FIG. 3. MODIFIED MARR APPARATUS FOR DETERMINING CARBON DIOXID. 



The apparatus required (Fig. 3), consists of a tube (A), 50-60 cm. long, partly 
filled with beads or broken glass and containing strong potassium hydroxid solution 
(1 to2), a cylindrical open top separatory funnel (B), capacity 50 cc, marked at 20 and 
40 cc, the stem of which extends almost to the bottom of the 250 cc. flask (C) into the 



20 METHODS OF ANALYSIS IChap. 

mouth of which is fitted, by means of a rubber stopper, a section of glass tubing 10 
cm. in length and 1 cm. internal diameter, which in turn is furnished witli a side 
tube extending through the condenser jacket (D), and connected by means of a rub- 
ber stopper to the small trap (K), which is attached to the Meyer absorption appara- 
tus {E) as shown in the figure. The Meyer absorption apparatus is provided with 2 
large bulbs, each of about 250 cc. capacity, and 10 smaller connecting bulbs, each of 
about 10 cc. capacity. The connections between the various bulbs should have an 
internal diameter of 8-10 mm. A perforated rubber stopper carrying 2 short pieces 
of capillary tubing each provided with rubber tubing and pinch-cocks {N and 0) 
is fitted into the other opening of the Meyer absorption apparatus; (A'^) is for the 
addition of reagents, (0) is connected to the vacuum pump. 

All parts of the apparatus must be capable of withstanding a vacuum of appro.xi- 
mately 70 cm. and be perfectly air tight. 

9 DETERMINATION. 

Place 5-20 grams of soil as prepared under 2 (depending upon the carbonate con- 
tent as indicated by qualitative examination) in the flask (C), and connect up the 
apparatus, but do not connect (A) to (B). Close the stop-cock (G) and the pnch- 
cock (N) ; open the pinch-cock (0) and exhaust the apparatus to a vacuum of ap- 
proximately 70 cm. Close the pinch-cock (0). Connect the barium hydroxid 
container by means of the pinch-cock (N) and rubber tube; open the pinch-cook 
(A^) and allow sufficient barium hydroxid solution to flow into the Meyer absorption 
apparatus to fill 3 or 4 of the small bulbs; close the pinch-cock (N); substitute the 
barium hydroxid container by the carbon dioxid-free water container; open the 
pinch-cock (A'^) and add sufficient carbon dioxid-free water to fill all the small bulbs 
and most of the lower large bulb. Through the separatory funnel (B), add 80 cc. of 
carbon dioxid-free water to the sample in the flask (C), avoiding the entrance of any 
air, open the pinch-cock (0) and heat to boiling, protecting the flask from the direct 
flame by a wire gauze with an asbestos center. Adjust the burner so that 2-3 min- 
utes are required for the contents of the flask to reach boiling temperature and boil 
until bubbles no longer pass through the Meyer absorption apparatus. Then close 
the pinch-cock (0), and run into the flask (C), avoiding the entrance of any air, 
20 cc. of the dilute hydrochloric acid through the separatory funnel which is then 
connected with the tube (A). This proportion of hydrochloric acid plus the 80 cc. of 
water previously added, gives an acid (2 to 100) for the decomposition of carbonates. 
If the nature of the soil is such that a greater strength of acid is considered necessary, 
an amount of acid (3 to 100) may be used for digesting the soil. 'Shake the Meyer 
apparatus (E) gently, so that the liquid in the lower large bulb is brought into con- 
tact with the gas therein, and open (0) carefully, but do not allow more than a few 
bubbles to escape before shaking again. Repeat the operation several times until 
bubbles no longer pass through the Meyer apparatus (E) when (0) is opened. Leave 
(0) open, and continue the boiling for about 25 minutes until carbon dioxid gas is 
no longer evolved from the sample in the flask (C). Maintain a constant flow of 
cold water through the condenser (D) . Do not allow the boiling to become so violent 
that liquid is drawn up into the condenser tube. If foaming is troublesome, add a 
drop of non-volatile oil through the separatory funnel (B). When the evolution of 
carbon dioxid has ceased, close (0) and break the vacuum by cautiously opening the 
stop-cock (G) drawing in air through the tube (A). 

Disconnect the Meyer apparatus {E) and filter by the Cain method^ as follows: 
Prepare a filter by covering a perforated porcelain plate within a carbon funnel with 
a layer of asbestos, and a layer of ground quartz, both of which have previously been 



II] SOILS 21 

purified by digestion with hydrochloric acid and thorough washing with water. 
The filter tube passes through a 1-holed rubber stopper which fits into a side arm 
filtering flask. The side arm of this flask is connected to the suction pipe by a 2-way 
stop-cock. In the top of the filter tube is fitted a 2-holed rubber stopper carrying 
glass tubes bent at right angles. To these tubes are attached rubber tubing bearing 
pinch-cocks. One of these rubber tubes terminates in a tube containing soda lime. 
The other rubber tube is connected with one end of the Meyer apparatus. The 
other end of the Meyer apparatus is attached to a bottle containing carbon 
dioxid-free water by means of a well-washed rubber tube and a glass tube extending 
to the bottom of the bottle. This glass tube passes through a 2-holed rubber stop- 
per. In the other hole of the stopper is placed a tube containing soda lime. A 
pinch-cock is placed on the tube joining the water bottle and the Meyer apparatus. 
This cock is kept closed until the precipitate on the filter is ready for washing. 
With the pinch-cock on the air outlet of the filter tube closed and the pinch-cock 
from the filter tube to the Meyer apparatus open, apply gentle suction to the 
filter flask until the contents of the Meyer apparatus have been transferred to the 
filter. When necessary, the pinch-cock to the air inlet of the filter tube is opened 
to admit air behind the liquid in the Meyer apparatus. Open the pinch-cock be- 
tween the wash-water bottle and the Meyer apparatus and open the stop-cock lead- 
ing from the filter flask so as to maintain a gentle suction. By manipulation of 
the Meyer apparatus the wash water comes in contact with all parts of the interior 
of the apparatus, after which the water is sucked through the filter. After this 
thorough washing admit air through the side opening of the stop-cock leading to the 
filter flask. 

Disconnect the apparatus, remove the filter pad with the barium carbonate from 
the filter tube by means of a glass rod, place in a beaker and add a measured amount 
of N/10 hydrochloric acid in excess, first rinsing the Meyer bulbs with a small amount, 
carefully measured, of this acid and water. Titrate the excess of acid with N/10 
sodium hydroxid, using methyl orange as indicator. Make a blank determination 
under the same conditions and apply the necessary correction. From the amount of 
N/10 hydrochloric acid required to neutralize the barium carbonate formed by the 
carbon dioxid in the sample, calculate the quantity of inorganic carbon. One cc. of 
N/10 acid corresponds to 0.0006 gram of carbon. 

10 TOTAL NITROGEN.— OFFICIAL. 

Place 7-14 grams of the soil, as prepared under 2, in a 300 cc. Kjeldahl digestion 
flask with 30 cc, or more if necessary, of concentrated sulphuric acid and 0.7 gram of 
mercuric oxid, or 0.65 gram of mercury. Mix immediately by shaking to prevent the 
soil from adhering to the sides of the flask. Heat over a low flame, increase the heat 
gradually, and rotate the flask frequently or shake if necessary to prevent the con- 
tents from sticking to the bottom of the flask. When all the organic matter is de- 
stroyed, continue the digestion for 1 hour. Oxidize the residue with potassium 
permanganate, carefully adding small portions at a time to the hot liquid until, after 
shaking, the liquid remains green or purple. After cooling, dilute the contents of 
the flaskwith 100 cc. of water and transfer to a 700 cc. copper flask, using about 150 cc. 
of water to wash out the digestion flask. Add an excess of strong alkali solution 
containing potassium sulphid, connect the flask with a distilling apparatus, mix the 
contents thoroughly and complete the determination as directed in I, 18. 



22 METHODS OF ANALYSIS [Chap. 

Strong Acid Digestion of the Soil 

1 1 preparation of soil solution —official. 

Place an amount of soil, as prepared under 2 and equivalent to 10 grams on a mois- 
ture-free basis, in a 200-300 cc. non-soluble glass Erlenmeyer flask to which is fitted, by 
a ground joint or 1-holed rubber stopper, a reflux tube 20 inches or more in length. 
Add lOOcc.of hydrochloric acid of constant boiling point (approximate sp. gr. 1.115, 
1350 cc. of acid (sp. gr. 1.19), and 1000 cc. of water), and digest continuously 
for 10 hours on a steam or water bath, shaking the flask every hour. Allow to settle, 
and avoiding more than very small quantities of the sediment, decant the solution 
into a porcelain dish or non-soluble glass beaker. Transfer by means of hot water 
the insoluble residue to a filter, wash until free from chlorin and add the washings 
to the original solution. Concentrate, oxidize the organic matter present in the 
solution with a few drops of nitric acid and evaporate to dryness on a water bath. 
Treat with hot water, add a few cc. of hydrochloric acid and again evaporate to com- 
plete dryness. When the final evaporation is complete and the dish cooled, moisten 
the residue with a few drops of strong hydrochloric acid. Add 10-20 cc. of water, 
warm on the bath to secure complete solution of the soluble salts, filter and wash 
until free from chlorin. Again evaporate the solution to dryness to render insoluble 
any silica that may remain in solution, and treat as above. The filtrate constitutes 
the acid extract freed of soluble silica, and is made up to a definite volume (250 or 500 
cc.) and designated as^. 

1 2 INSOLUBLE RESIDUE.— OFFICIAL. 

Combine the filters and the main residue obtained in 1 1 in a small dish, dry, ignite 
over a Bunsen flame for an hour or more, carefully at first, then completely over 
a blast lamp to constant weight. Weigh and calculate as the insoluble residue. 
This residue may be analyzed by the usual methods applicable to silicates or it may 
be employed in the determination of total alkalies as described under 26. If it is 
desired to determine the silica soluble in alkalies, treat a separate portion of the soil 
as directed in 11, except that all filtrations must be made through the same hard- 
ened filter, then, without igniting, wash the insoluble residue into a platinum dish, 
dry at 100°C. and complete the determination as directed under III, 4 (a). 

13 IRON, ALUMINIUM AND PHOSPHORIC ACID, COLLECTIVELY.— OFFICIAL. 

(1) To an aliquot (50 or 100 cc, according to the probable amount of iron 
present) of A, under 11, add ammonium hydroxid, drop by drop, until the precipi- 
tate formed requires several seconds to dissolve, thus leaving the solution but faint- 
ly acid. Heat nearly to the boiling point, and add ammonium hydroxid to precipi- 
tate all of the iron, aluminium, etc. Boil in a covered beaker for about 1 minute, 
remove, and if no ammonia is given off (detected by smelling) continue the addi- 
tion, drop by drop, until ammonia can be detected. Do not allow the precipitate 
to settle, but stir and pour on the filter. Wash immediately with hot water, using a 
fine jet which is played around the edge of the precipitate, thus cutting it free 
from the paper in order to produce rapid filtration. Wash the precipitate several 
times, return it to the original beaker, dissolve with a few drops of hydrochloric 
acid and warm. Reprecipitate the iron, aluminium and phosphoric acid with 
ammonium hydroxid as above and wash until free from chlorin. Designate the 
filtrate as B. 

Dry the filter and precipitate, remove the latter from the filter, ignite the filter 
separately and add to its ash the precipitate. Then ignite to bright redness, cool 



II] SOILS 23 

in a desiccator and weigh as ferric oxid (Fe203), aluminium oxid (AI2O3), and phos- 
phorus pentoxid (P2O5). Transfer this residue to a flask, digest with several cc. 
of sulphuric acid (1 to 4), and heat to accelerate solution. When solutionis complete 
reduce with zinc and determine the ferrous iron by titration with a standard per- 
manganate solution, and calculate to ferric oxid; or, (2) In lieu of the above, evapo- 
rate 50 or 100 cc. of A, under 11 , with the addition of 10 cc. of su phuric acid until all 
hydrochloric acid is expelled, dilute with water, reduce with zinc and determine the 
ferrous iron by titration with a standard permanganate solution and calculate to 
ferric oxid. 

The weight of ferric oxid, plus that of the phosphorus pentoxid, determined 
under 17 or 19, subtracted from the collective weight of ferric oxid, aluminium 
oxid, and phosphorus pentoxid, gives the weight of the aluminium oxid. 



14 



MANGANESE.— OFFICIAL. 



Concentrate B, under 13, to about 50 cc, cool, add brominwater until the solution 
is colored, make alkaline with ammonium hydroxid, and heat to boiling in a covered 
beaker; cool, and repeat the addition of bromin water, of ammonium hydroxid and 
boil again. If a precipitate is obtained, slightly acidify the solution with acetic 
acid, filter immediately, and wash with hot water. Dry the precipitate, ignite and 
weigh as manganomanganic oxid (Mn304). Designate the filtrate, or if there is no 
precipitate, the original solution, as C. 

1 5 CALCIUM.— OFFICIAL. 

Concentrate C, under 14, to about 50 cc, make slightly alkaline with ammonium 
hydroxid, and add, while still hot, ammonium oxalate solution, drop by drop, slightly 
in excess of complete precipitation, to convert the magnesium also into oxalate. 
Heat to boiling, allow the precipitate to settle completely, decant the clear solution 
on a filter, pour 15-20 cc. of hot water on the precipitate, and again decant the clear 
solution on the filter. Dissolve the precipitate in the beaker with a few drops of 
hydrochloric acid add a little water, repeat the precipitation as above, and filter 
through the same filter; transfer the precipitate to the filter and wash free from chlo- 
rin with hot water; dry, ignite the precipitate over the blast lamp to constant weight, 
and weigh as calcium oxid. Designate the filtrate and washings as D. 



16 



MAGNESIUM.— OFFICIAL. 



Evaporate D, under 1 5, to dryness on the water bath and heat carefully to expel 
ammonium salts. Treat the residue with 20-25 cc. of hot water and about 5 cc. of 
hydrochloric acid, filter and wash. Concentrate to about 50 cc, cool, and add suffi- 
cient disodium hydrogen phosphate solution to precipitate the magnesium; then 
add gradually ammonium hydroxid, with constant stirring, until the solution is 
distinctly alkaline. Determine if the precipitation is complete by the addition of 
more of the disodium hydrogen phosphate solution. After 30 minutes, add gradually 
10 cc of strong ammonium hydroxid, cover to prevent the escape of ammonia, and 
let stand in the cold. Filter after 12 hours, wash the precipitate free from chlorin, 
using dilute ammonium hydroxid [I, 4 (d)], dry the filter and precipitate and trans- 
fer the latter to a weighed porcelain crucible. Ignite the filter separately and add 
its ash to the precipitate in the crucible. Burn at first at a moderate heat, then 
ignite to whiteness or to a grayish white, weigh as magnesium pyrophosphate 
(Mg2P207) and calculate to magnesium oxid (MgO). 



24 METHODS OF ANALYSIS [Chap. 

PHOSPHORIC ACID. 

17 Gravimetric Method. — Official. 

Concentrate 100-200 cc. of A, under 1 1 , to about 25-30 cc, neutralize with ammo- 
nium hydroxid and add about 10 cc. additional. Dissolve the precipitate by the slow- 
addition of dilute nitric acid, stirring constantly and avoiding a large excess, add 
gradually about 20 cc. of molybdate solution [I, 4 (a) ], and allow to stand for 1 or 2 
hours in a water bath at a temperature of 40°C. After an hour determine if the 
precipitation is complete, as follows: Pipette about 5 cc. of the clear liquid into 5 cc. 
of warm molybdate solution. If any precipitate is produced, return the test liquid 
to the main portion, add more molybdate solution, and repeat the operation until 
all the phosphoric acid is precipitated. Then allow to stand for several hours at 
room temperature, preferably overnight. Filter off the ammonium phosphomolyb- 
date, wash the precipitate thoroughly with cold water, dissolve with ammonium 
hydroxid, and determine as magnesium pyrophosphate, as directed under I, 6 and 
calculate to phosphorus pentoxid (P2O5). 

Volumetric Method. — Tentative. 

18 REAGENTS. 

(a) Standard sodium or potassium hydroxid solution. — Strength such that 1 cc. 
of this solution is equivalent to 0.0005 gram of phosphorus pentoxid (P2O5). 

(b) Standard nitric acid solution. — Strength same as the standard alkali solution 
described under (a) as determined by titration, using phenolphthalein as indicator. 

19 DETERMINATION. 

Proceed as in 17 until all the phosphoric acid is precipitated and then complete 
the determination in the following manner: 

Allow the solution containing the yellow precipitate to stand for at least 3 hours 
at a temperature not above 40°C., filter on a small filter paper or on a Gooch crucible 
and wash with cold water until the filtrate from 2 fillings of the filter yields a slight 
pink color on the addition of phenolphthalein and 1 drop of the standard alkali. 
Return the filter and precipitate to the same beaker used for precipitating the 
phosphomolybdate, dissolve the yellow precipitate in the standard sodium or potas- 
sium hydroxid solution, add a few drops of phenolphthalein and titrate the excess of 
alkali with the standard acid. Calculate to phosphorus pentoxid (PzOj). 

20 SULPHURIC ACID.— OFFICIAL. 

Evaporate 100-200 cc. of .4, under 11, nearly to dryness on a water bath to expel 
the excess of acid, add 50 cc. of water, heat to boiling and add, drop by drop, 10% 
barium chlorid solution until no further precipitation occurs. Continue the boiling 
for about 5 minutes and allow to stand for 5 hours or longer in a warm place. Decant 
the liquid on an ashless filter or tared Gooch, previously heated, treat the precipitate 
with 15-20 cc. of boiling water, transfer to the filter and wash free from chlorin with 
boiling water. Dry the precipitate and filter, ignite, weigh as barium sulphate and 
calculate to sulphur trioxid (SO3). 

POTASSIUM AND SODIUM. 

21 Method I.— Official. 

(1) Treat the filtrate from 20 with ammonium hydroxid exactly as in 13. 
Evaporate the filtrate and washings to dryness, heat below redness until ammo- 
nium salts are expelled, dissolve in hot water, add 5 cc. of barium hydroxid solution. 



II] SOILS 25 

and heat to boiling; let settle for a few minutes, and determine if the precipitation 
is complete by the addition of barium hydroxid solution to a little of the clear liquid. 
When no further precipitate is produced, filter and wash thoroughly with hot water. 
Heat the filtrate to boiling, add ammonium hydroxid and ammonium carbonate to 
complete the precipitation of the barium, calcium, etc., let stand a short time on the 
water bath, filter, and wash the precipitate thoroughly with hot water; evaporate 
the filtrate and washings to dryness, expel ammonium salts by heating below red- 
ness, treat with a little hot water, add a few drops of ammonium hydroxid, 1 or 2 
drops of ammonium carbonate, and a few drops of ammonium oxalate; let stand 
a few minutes on the water bath, set aside for a few hours, filter, evaporate to complete 
dryness on the water bath, and heat to dull redness until all ammonium salts are 
expelled and the residue is nearly or quite white. Dissolve in a minimum amount 
of water, filter into a tared platinum dish, add a few drops of hydrochloric acid, evap- 
orate to dryness on the water bath, heat to dull redness, cool in a desiccator, and 
weigh as potassium and sodium chlorids. Repeat the heating until constant weight 
is obtained. Dissolve in a small amount of water; if any residue remains, the sepa- 
ration must be repeated until the residue of potassium and sodium chlorids is entirely 
soluble. Dissolve the residue with water, add an excess of platinic chlorid solution 
[1, 40 (b)], proceed as directed under 1, 45 and calculate to potassium oxid (K2O) ; or, 
(2) Instead of the foregoing, evaporate to dryness a fresh aliquot of A, under 11, 
redissolve in water, treat directly with barium hydroxid solution, and from this point 
proceed as directed above in (1). 

22 Method II.— Tentative. 

Proceed as in 21 through "let stand a short time on the water bath" (the point 
at which the barium, calcium, etc., have been precipitated with ammonium hydroxid 
and ammonium carbonate) and then proceed as follows: 

Filter into a beaker, add 1 or 2 drops of hydrochloric acid and 1 cc. of ammonium 
sulphate (75 grams to 1 liter), digest several hours on a water bath, and filter into a 
tared platinum dish. Evaporate to dryness, heat to full redness, add 1 gram of 
powdered ammonium carbonate; heat to expel excess of ammonium carbonate, 
cool, and weigh the sulphates of sodium and potassium. Determine potassium as 
directed under I, 42 (a) and calculate to potassium oxid (K2O). 

TOTAL PHOSPHORUS. 

23 Magnesium Nitrate Method. — Official. 

Place 5 grams of soil, as prepared under 2, in a porcelain dish. Moisten with 5-7 
cc. of magnesium nitrate solution [I, 4 (6) ]. Dry on the water bath and burn off 
the organic matter at low redness. Cool, moisten slightly with water, add 10 cc. of 
concentrated hydrochloric acid, and digest 2 hours on the water bath, keeping the 
dish covered with a watch glass and stirring 2 or 3 times during the digestion. Trans- 
fer to a 250 cc. graduated flask, cool, fill to the mark, mix well, and pass through 
a dry folded filter, pouring back on the filter until the filtrate becomes clear. Pipette 
an aliquot corresponding to 2 or 4 grams of the soil, depending upon the amount 
of phosphorus present, into a porcelain dish, evaporate to dryness, treat with hydro- 
chloric acid and water, filter, and wash; the combined volume should not exceed 
40 cc. Make alkaline with ammonium hydroxid, and dissolve the precipitate by 
the slow addition of concentrated nitric acid, using a slight excess. Add gradu- 
ally, while shaking, 5-15 cc. of molybdate solution [I, 7 (a) ]. Keep the solution 
at 40°-50°C. for an hour, let stand overnight at room temperature, filter, and wash 
well with cold water. Return the filter and precipitate to the same flask and deter- 
mine phosphorus volumetrically, as directed under 19. 



26 METHODS OP ANALYSIS [Chap. 

24 Sodium Peroxid Method. — Official. 

Place 10 grams of sodium peroxid in an iron or porcelain crucible and thoroughly 
mix with 5 grams of the soil as prepared under 2. If the soil has very little organic 
matter, add a little starch to hasten the action. Heat the mixture carefully by 
applying the flame of a Bunsen burner directly upon the surface of the charge and 
the sides of the crucible until the action starts. Cover the crucible until the re- 
action is over and keep at a low red heat for 15 minutes. Do not allow fusion to 
take place. By means of a large funnel and a stream of hot water, wash the charge 
into a beaker, acidify with hydrochloric acid and boil. Transfer to a 500 cc. gradu- 
ated flask, cool and fill to the mark. If the action has taken place properly there 
should be no undecomposed soil in the bottom of the flask. Allow the silica to 
settle and draw off 200 cc. of the clear solution. 

Precipitate the iron, aluminium, and phosphorus with ammonium hydroxid; 
filter, wash several times with hot water, wash the precipitate back into the beaker 
with a stream of hot water, and dissolve the precipitate in hot hydrochloric acid, 
pouring the acid upon the filter to dissolve any precipitate adhering to it. Evapo- 
rate the solution and washings to dryness on a water bath. Treat with dilute hy- 
drochloric acid, heating if necessary, and remove the silica by filtration. Con- 
centrate the filtrate and washings to about 10 cc, add 2 cc. of strong nitric acid, 
and make alkaline with ammonium hydroxid. Add nitric acid very slowly and with 
constant stirring until the solution is clear, avoiding an excess. Heat at 40°-50°C. 
on a water bath, add 15 cc. of molybdate solution, [I, 7 (a) ], and maintain this tem- 
perature for 1-2 hours. Let stand overnight, filter, and wash free from acid with 
0.1% solution of ammonium nitrate, and, finally, once or twice with cold water. 
Transfer the filter and precipitate to the same beaker and determine phosphorus 
volumetrically as directed under 19. 

25 TOTAL POTASSroM.— OFFICIAL. 

Decompose the soil by the J. L. Smith method^ as follows: Triturate gently 
0.5 or 1 gram of the finely ground soil with 1 gram of dry ammonium chlorid in a 
smooth mortar, then add 8 parts of calcium carbonate and mix intimately. Trans- 
fer the mixture to a platinum crucible, rinsing the mortar with a little calcium car- 
bonate. Heat the crucible gradually until fumes of ammonium salts no longer 
appear, and continue until the lower three-fourths only of the crucible are brought 
to a red heat. Maintain this temperature 40-60 minutes. The temperature should 
be sufficient to keep the calcium chlorid formed by the reaction of ammonium chlo- 
rid with calcium carbonate in a state of fusion. The mass, however, does not be- 
come liquid since the fused calcium chlorid is absorbed by the large quantity of 
calcium carbonate present. If the silicate is fused by the application of too strong 
heat, disintegration of the mass at the end of the operation with water cannot be 
effected. Moreover, too high a temperature causes volatilization of alkali chlorids. 
The mass contracts in volume during the ignition, and is usually easily detached 
from the crucible. Transfer the fused mass to a porcelain dish, thoroughly slake 
with hot water, and grind thoroughly with an agate pestle. After washing 5 times 
by decantation with hot water, transfer to a filter and wash well, 300 cc. of wash 
water being sufficient. To the filtrate add 10 cc. of concentrated hydrochloric 
acid, and evaporate nearly to dryness in a porcelain dish. Treat with hot water 
and 2 cc. of hydrochloric acid and filter by means of suction through a small filter 
into a 150 cc. Jena beaker. Concentrate the solution to 30 cc, add 1.5 cc. of platinic 
chlorid solution [I, 40 (b) ], evaporate to a sirupy consistency, and add 15 cc of 
2.25 N/1 acidulated alcohol (prepared by passing hydrochloric acid gas into a mix- 



II] SOILS 27 

ture of 2000 cc. of 95% alcohol and 152 cc. of hydrochloric acid, sp. gr. 1.20). Fil- 
ter by means of suction through a small filter, wash with 80% alcohol, then with 
ammonium chlorid solution [I, 40 (a) ], and finally with 80% alcohol. Dry the 
precipitate on the filter and wash the precipitate with hot water into a weighed 
platinum dish, using suction. Evaporate to dryness, heat in a drying oven for 
an hour at 120°C., cool in a desiccator, weigh and calculate to potassium oxid (K2O). 

TOTAL ALKALIES. 

26 /. Lawrence Smith Method.* — Official. 

(1) Proceed as directed under 25 to the point indicated by the phrase "300 cc. of 
wash water being sufficient" (the point at which the ignited mass has been 
disintegrated and thoroughly washed with water). The filtrate contains the sili- 
cate alkalies in the form of chlorids together with calcium chlorid and hydroxid. 
Precipitate the calcium at once with ammonium carbonate solution; allow to settle, 
decant the supernatant liquid into a porcelain (or platinum) dish, concentrate and 
finally transfer the precipitate to the dish. When the volume is reduced to about 
30 cc, add a little ammonium carbonate solution and ammonium hydroxid, heat 
and filter into a porcelain (or platinum) dish, evaporate the filtrate to dryness on 
a water bath and expel ammonium salts by ignition. Dissolve the residual alkali 
chlorids in 3-5 cc. of water; a little black or dark brown flocculent matter usually 
remains undissolved, while the solution may also contain traces of calcium. Add 
2-3 drops of ammonium carbonate and ammonium hydroxid, warm gently, and fil- 
ter through a very small filter into a weighed platinum vessel. Evaporate to dry- 
ness on a water bath, heat the alkali chlorids to incipient fusion, cool, and weigh 
as sodium and potassium chlorids; or, 

(2) Determine, by the above method, the quantity of alkalies in the insoluble 
residue, 12, and add that obtained under 21 or 22. 

27 PHOSPHORUS SOLUBLE IN N/5 NITRIC ACID.— TENTATIVE. 

Digest 10 grams of air-dried soil in a stoppered flask, with 100 cc. of N/5 nitric 
acid, for exactly 5 hours in a water bath kept at a temperature of 40°C. Filter the 
solution through a dry paper, cool to room temperature, and titrate 20 cc. of the 
filtrate with standard potassium hydroxid solution (carbonate-free), using phenol- 
phthalein as indicator. From the data thus secured calculate the number of cc. 
of N/1 acid and of water to make exactly 1 or 2 liters of acid of N/5 strength after 
allowing for the quantity neutralized by the amount of soil to be used in the fol- 
lowing procedure: 

Place 200 grams of the air-dried soil in a large, dry, glass-stoppered bottle and 
add exactly 2000 cc. of N/5 nitric acid corrected for neutralization as above de- 
scribed. With soils rich in available phosphoric acid, 100 grams of soil and 1000 cc. 
of acid will be sufficient. Digest in a large water bath at a temperature of 40°C. 
for exactly 5 hours, shaking thoroughly each half hour. At the end of the digestion 
shake the contents of the bottle well and pour quickly upon a large, dry, ribbed fil- 
ter of 2 thicknesses of paper and of sufficient size to receive the entire contents of 
the bottle. Collect the filtrate in a dry vessel, pouring back on the filter until the 
filtrate becomes clear. Evaporate 1000 or 500 cc. of the filtrate, according to the 
quantity of soil used, to dryness in a porcelain dish; add a few cc. of nitric acid to 
oxidize organic matter, etc., moisten the residue with hydrochloric acid, digest 
with water, and filter into a 500 cc. flask. Add a solution containing 15 grams of 
ammonium nitrate; then strong ammonium hydroxid until a permanent precipitate 
forms, and then concentrated nitric acid slowly until the precipitate dissolves. 



28 METHOD OF ANALYSIS 

Dilute to about 100 cc, if less than that volume, place a thermometer in the flask, 
and heat to 85°C. Add 75 cc. of recently prepared molybdate solution [I, 4 (a) ], 
digest in a water bath at 80°C. for 15 minutes, with occasional shaking, remove from 
the bath and allow to stand at least 10 minutes before filtering. Continue the de- 
termination as directed under I, 6 and calculate to phosphorus pentoxid (P2O6). 

28 CALCIUM CARBONATE REQUIRED.— TENTATIVE. 

Place 100 grams of soil, as prepared under 2, in a 400 cc. wide-mouthed bottle, 
add 250 cc. of N/1 potassium nitrate, stopper, and shake continuously for 3 hours 
in a shaking machine, or every 5 minutes by hand. Let stand overnight. Draw 
off 125 cc. of the clear, supernatant liquid, boil 10 minutes to expel carbon dioxid, 
cool, and titrate with standard sodium hydroxid solution, 1 cc. of which is equiva- 
lent to 4 mg. of calcium carbonate (0.001% on basis of the weight of soil used), using 
phenolphthalein as indicator. 



STATEMENT OF RESULTS.— OFFICIAL. 



29 

Calculate all results of soil analysis as per cent of the soil dried to constant weight 
as under 3 and state in the following order: 

Insoluble residue 

Soluble silica 

Manganomanganic oxid (Mn304) 

Potassium oxid (K2O) 

Sodium oxid (Na20) 

Calcium oxid (CaO) 

Magnesium oxid (MgO) , 

Ferric oxid (Fe203) 

Aluminium oxid (AI2O3) 

Phosphorus pentoxid (P2O5) 

Sulphur trioxid (SO3) 

Organic carbon 

Inorganic carbon 

Volatile matter 

Total nitrogen 

Total phosphorus 

Total potassium 

Phosphorus soluble in N/5 acid 

Calcium carbonate required 

Total 

BIBLIOGRAPHY 

1 J. Am. Chem. Soc, 1904, 26: 294, 1640. 

2 J. Agr. Sci., 3: (II), 155. 

3 J. Ind. Eng. Chem., 1914, 6: 465. 

^ Fresenius. Quantitative Chemical Analysis. Revised and amplified transla- 
tion of the 6th German ed., 1906, 2: 1175; Crookes. Select Methods in Chemical 
Analysis. 4th ed., 1905, p. 23; Wiley. Principles and Practice of Agricultural 
Analysis. 1906, 1: 423; U.S. Geol. Surv. Bull. 422, p. 171; Am. J. Sci., 2nd ser., 
1871, 50: 269; Am. Chem., 1871, 1; Ann. Chem. Pharm., 1871, 159: 82. 



III. PLANT CONSTITUENTS. 

1 PREPARATION OF SAMPLE.— OFFICIAL. 

Thoroughly cleanse the material from all foreign matter, especially from adhering 
soil, air-dry, grind, and preserve the sample in tightly stoppered bottles. 

2 PREPARATION OF ASH.— OFFICIAL. 

Ignite 10-20 grams of the substance, in a flat-bottomed platinum dish in a muffle, 
at a comparatively low temperature. Do not employ a full red heat because of the 
danger of volatilizing alkali chlorids, etc. If rich in silica and alkalies, char the 
material, treat with water to dissolve soluble salts, filter through an ashless filter, 
dry the filter and paper and incinerate, add the filtrate to the incinerated residue, 
evaporate to dryness and ignite at a low red heat. If rich in phosphates, e.g., seeds 
and animal substances, char the material, dissolve soluble salts in dilute acetic 
acid, filter through an ashless filter, wash with water, dry and incinerate the filter 
and residue, add the filtrates to the incinerated residue, evaporate to dryness, and 
ignite gently. While still warm, pulverize the whole of the ash as obtained above, 
mix intimately and preserve in a tightly stoppered, dry bottle. If after incineration 
the ash has absorbed moisture, dry thoroughly at low redness before bottling. 

3 CARBON DIOXID.— OFFICIAL. 

Determine carbon dioxid in a weighed portion of the ash prepared under 2. Lib- 
erate the carbon dioxid by treatment with dilute hydrochloric acid in any of the 
usual forms of apparatus, and determine the increase in weight of the potash 
bulbs. The efficiency of the apparatus should be tested by blank determinations 
conducted upon weighed portions of pure calcite. 

4 CARBON, SAND AND SILICA.— OFFICLAlL. 

Transfer the residue from the carbon dioxid determination to a beaker or evapo- 
rating dish; evaporate to dryness; pulverize and dry thoroughly to render the silica 
insoluble. Moisten the dry residue with 5-10 cc. of hydrochloric acid, add about 
50 cc. of water, allow to stand on the water bath for a few minutes, filter through 
a hardened filter and wash thoroughly. Dilute the solution and washings to 250 
cc. or other convenient volume. Designate as A. 

Wash the residue from the filter into a platinum dish and boil for about 5 minutes 
with approximately 20 cc. of a saturated solution of pure sodium carbonate, add a 
few drops of pure sodium hydroxid solution, allow the solution to settle and decant 
through a tared Gooch filter. Boil the residue in the dish with sodium carbonate 
solution and decant as before. Repeat the process again, then transfer the residue 
to the Gooch filter, wash thoroughly, first with hot water, then with a little dilute 
hydrochloric acid, and finally with hot water until free from chlorin. Dry the filter 
and contents to constant weight at 110°C. to determine the combined weight of 
carbonaceous material and sand. Incinerate; the loss in weight represents the 
carbonaceous material; the residue is sand. Confirm by microscopic examination. 
Determine the soluble silica as follows: (1) Combine the alkaline filtrate and wash- 
ings, acidify with hydrochloric acid, evaporate to dryness and determine the silica 

29 



30 METHODS OF ANALYSIS [Chap. 

in the usual way; or, (2) Treat a weighed portion of the ash, as prepared under 2, 
with dilute hydrochloric acid. Evaporate to dryness; pulverize and dry thoroughly 
to render the silica insoluble. Moisten the dry residue with 5-10 cc. of hydrochloric 
acid, add about 50 cc. of water, allow to stand on. the water bath for a few minutes, 
filter on an ashless filter, wash, dry, ignite and weigh to determine the combined 
weight of the silica and sand. Deduct the weight of the sand found above to obtain 
that of the silica. The soluble silica cannot be separated from the residue after 
ignition. 

5 CARBON-FREE ASH.— OFFICIAL. 

Subtract the weights of the carbon found in 4 and the carbon dioxid found in 3 
from that of the total ash used in 3. 

6 FERRIC AND ALUMINIUM OXIDS.— OFFICIAL. 

(Applicable for plant materials other than seeds.) 

Pipette an aliquot of A, under 4, corresponding to 0.5 gram of ash, into a 250 cc. 
beaker. If ferrous iron is present, oxidize it by boiling with a few cc. of hydrogen 
peroxid or of concentrated nitric acid. Cool, add ammonium hydroxid until a 
precipitate begins to form, then nitric acid until just clear, and finally add 2-3 cc. 
of concentrated nitric acid in excess. Add 25 cc. of 50% ammonium nitrate solution, 
phosphate free, heat to 40°C., and add slowly, with constant shaking, a moderate 
excess of molybdate solution [1, 4 (a)], and allow to stand for 1 or 2 hours at a tem- 
perature not exceeding 40°C. After standing for an hour pipette 5 cc. of the clear 
solution into an equal volume of warm molybdate solution. If a precipitate forms 
in the test portion return it to the original solution and add more molybdate solu- 
tion. Allow to stand at room temperature for several hours, preferably overnight. 
Filter, wash with about 75 cc. of ammonium nitrate solution (2.5%, phosphate free, 
and slightly acidified with nitric acid) and combine the filtrate and washings. Des- 
ignate as B. Reserve the precipitate for the determination of phosphoric acid as 
described under 1 1 . 

Without concentrating solution B, cautiously neutralize with ammonium hydroxid, 
add a very slight excess of the alkali, avoiding a temperature higher than 40°C., and 
allow to stand at this temperature until the precipitate completely settles. Filter 
the clear supernatant liquid, wash the precipitate a few times by decantation with 
hot water before transferring to the filter, then wash 4 or 5 times on the filter. Dis- 
solve the precipitate on the filter with hot nitric acid (1 to 5), wash and reprecipitate 
as before. The combined filtrates and washings from the first and second precipi- 
tations should not exceed 500 cc. and should not be concentrated by evaporation. 
Designate as C and reserve for the determination of calcium and magnesium as 
described under 8. The same filter may be used for the second filtration, and the 
volume of the solution for the reprecipitation need not exceed 100 cc. Before the 
second filtration is made, a small quantity of ashless filter paper pulp should be 
added in order to facilitate the washing and leave the precipitate finely divided 
after the ignition, so that it can be easily fused with potassium hydrogen sulphate for 
the iron determination. Dry and ignite the precipitate and weigh as ferric and 
aluminium oxids. 

The iron oxid is determined in the following manner: Fuse, in a platinum crucible, 
the ignited precipitate with about 4 grams of fused potassium h5'drogen sulphate. 
This fusion takes but a few minutes and must not be continued beyond the time 
actually needed. When completed the crucible is set aside and allowed to cool. 
Add 5 cc. of concentrated sulphuric acid and heat until copious fumes of sulphuric 



ni] PLANT CONSTITUENTS 31 

acid are given off. Cool, transfer to a flask, add water, and digest till the solution is 
clear. Reduce with zinc, cool, titrate with N/50 potassium permanganate and cal- 
culate to ferric oxid. 

If it is desired to use a larger amount of the sample for the iron determination, 
evaporate a suitable aliquot of A, under 4, with sulphuric acid, reduce with zinc, 
and titrate as above. 

MANGANESE, CALCIUM AND MAGNESIUM. 

(Applicable for plant materials other than seeds.) 

7 Method I.— Official. 

To an aliquot of A, under 4, corresponding to 0.5-2 grams of ash, add a quantity 
of pure ferric chlorid solution, more than sufficient to combine with the phosphoric 
acid which may be present, and neutralize with ammoniuna hydroxid. Dissolve the 
precipitate in a very slight excess of hydrochloric acid and add 1-2 grams of sodium 
acetate. Boil for 1-2 minutes, filter at once, and wash with boiling water. Dissolve 
the precipitate in hydrochloric acid and reprecipitate as above. Concentrate the 
combined filtrates and washings to about 50 cc. and determine manganese, calcium 
and magnesium as directed under II, 14, 15, and 16. 

8 Method II.— Tentative. 

Calcium. — Make alkaline with ammonium hydroxid the combined filtrates and 
washings, C, under 6, and proceed as directed under II, 15. If the ignited calcium 
oxid has a brown coloration, due to manganese, dissolve in dilute hydrochloric acid 
and determine the manganese as directed below. Deduct the weight of mangano- 
manganic oxid thus obtained from the weight of the impure calcium oxid. 

Manganese. — Acidify the combined filtrates and washings from the calcium de- 
termination and evaporate to dryness in a porcelain casserole. Expel the ammonium 
salts by carefully heating the casserole from above, treat with a few cc. of hydro- 
chloric acid and water, filter off molybdic acid, and wash the precipitate until it is 
free from chlorin. Bring the filtrate to a volume of 100 cc, add 1-2 drops of bromin, 
make alkaline with ammonium hydroxid and let stand for several minutes without 
agitation. Filter off the precipitated manganese, wash, dry, ignite, and weigh the 
precipitate as manganomanganic oxid. To this add the weight of the mangano- 
manganic oxid found as an impurity in the calcium determination. 

Magnesium. — Concentrate the alkaline filtrate from the manganese determination 
to 75 cc. and determine magnesium as directed under II, 16. 

PHOSPHORIC ACID. 

9 Method I.— Official. 

Determine phosphoric acid in an aliquot of A, under 4, corresponding to 0.2-1 
gram of ash, as directed under I, 6 or 9. 

10 Method II. —Official. 

Determine phosphoric acid in the plant substance as directed under 1,6, using suf- 
ficient material to give 0.2-1 gram of ash in the aliquot of the solution employed. 

11 Method III. —Official. 

The phosphomolybdate precipitate obtained in 6 is used for the determination 
of phosphoric acid as directed under I, 6, beginning with "Dissolve the precipitate 



32 METHODS OF ANALYSIS [Chap. 

on the filter with ammonium hydroxid, etc." or as under I, 9 (a), beginning with 
"Wash with cold water until the filtrate from 2 fillings of the filter yields a pink 
color, etc." 

12 SULPHURIC ACID, SODIUM, AND POTASSIUM.— OFFICIAL. 

Boil an aliquot of A, under 4, corresponding to 0.5-1 gram of ash, add barium 
chlorid solution in small quantities until no further precipitate is formed, and pro- 
ceed as directed under II, 20 and 21 . 

13 CHLORIN.— OFFICIAL. 

Determine as silver chlorid, either gravimetrically or by one of the standard 
volumetric procedures (as the Volhard method given below), in a nitric acid or 
aqueous solution of the ash. 

Volhard Method.^ 

14 REAGENTS. 

(a) N/10 silver nitrate. 

(b) N /lO ammonium or potassium sulphocyanate. 

(C) Ferric indicator. — Saturated solution of ferric alum. 

(d) Nitric acid. — Free from lower oxids of nitrogen, secured by diluting the 
usual pure acid with about 1/4 part of water, and boiling till perfectly colorless. 

15 DETERMINATION. 

Dissolve a weighed portion of the ash, prepared under 2, in nitric acid (1 to 10), 
filter and wash with water. Add a known volume of the N/10 silver nitrate in slight 
excess to the combined filtrate and washings. Stir well, filter, and wash the silver 
chlorid precipitate thoroughly. To the filtrate and washings add 5 cc. of the ferric 
indicator and a few cc. of the nitric acid. Titrate the excess of silver with the 
N/10 sulphocyanate until a permanent light brown color appears. Calculate the 
amount of chlorin. 

16 POTASSIUM IN PLANTS.— OFFICIAL. 

Determine potassium as directed under I, 42, using sufficient plant material to 
yield 0.5-1 gram of ash in the aliquot of the solution used for the potassium determi- 
nation. 

SULPHUR IN PLANTS. 

17 Peroxid Method. — Official. 

Place 1.5-2.5 grams of material in a nickel crucible of about 100 cc. capacity and 
add 5 grams of pure anhydrous sodium carbonate. Mix thoroughly, using a nickel or 
platinum rod, and moisten with approximately 2 cc. of water. Add pure sodium 
peroxid, approximately 0.5 gram at a time, thoroughly mixing the charge after each 
addition. Continue adding the peroxid until the mixture becomes nearly dry and 
quite granular, requiring usually about 5 grams of peroxid. Place the crucible over 
a low alcohol or other sulphur-free flame and heat carefully with occasional stirring 
until the contents are fused. (Should the material ignite, the determination is 
worthless.) After fusion remove the crucible, allow to cool somewhat, and cover the 
hardened mass with peroxid to a depth of about 0.5 cm. Heat gradually, and finally 
with full flame until fusion again takes place, rotating the crucible from time to 
time in order to bring any particles adhering to the sides into contact with the 
oxidizing material. Continue the heating for 10 minutes after fusion is complete. 



ni] PLANT CONSTITUENTS 33 

Cool somewhat, place the warm crucible and contents in a 600 cc. beaker and care- 
fully add about 100 cc. of water. After the initial violent action has ceased, wash 
the material out of the crucible, make slightly acid with hydrochloric acid (adding 
small portions at a time), transfer to a 500 cc. flask, cool, and make to volume. 
Filter, and determine sulphates in 200 cc. of the filtrate as directed under II, 20. 

18 CHLORIN IN PLANTS.— TENTATIVE. 

Moisten 5 grams of the substance in a platinum dish with 20 cc. of a 5% solution of 
sodium carbonate, evaporate to dryness, and ignite as thoroughly as possible at a 
temperature not exceeding dull redness. Extract with hot water, filter and wash. 
Return the residue to the platinum dish and ignite to an ash; dissolve in nitric acid, 
add this solution to the water extract and determine chlorin as directed under 15. 

BIBLIOGRAPHY. 
' Sutton. Volimietric Analysis. 10th ed., 1911, p. 145. 



IV. WATERS. 
POTABLE WATER. 

TURBIDITY.— TENTATIVE. 

1 REAGENTS. 

(a) Standard turbidity solution.— ^eigh out 1 gram of elutriated fuller's earth 
previously dried and sifted through a 200 mesh sieve. Make up to a liter. If the 
fuller's earth is of goodquality and the proper degree of fineness, this stock solution 
has a turbidity of 1000. Check the stock solution with a Jackson turbidimeter. 

(b) Turbidity standards. — Prepared by dilution of (a). 

2 DETERMINATION. 

Determine the turbidity of the sample with a Jackson turbidimeter equipped 
with either candle or electric light. If the turbidity is less than 100, which pro- 
hibits the use of the turbidimeter, determine by direct comparison with turbidity 
standards contained in bottles of clear white glass. 

COLOR.— TENTATIVE. 

3 ■ REAGENTS. 

(a) Standard color solu' ion. —Dissolve 1.246 grams of potassium platinic chlorid 
(PtCi42KCl) and 1 gram of crystallized cobalt chlorid (C0CI26H2O) in a small quan- 
tity of water, add 100 cc. of concentrated hydrochloric acid and make up to 1 liter 
with water. This stock solution has a color of 500. 

(b) Color standards. — Prepared by dilution of (a). 

4 DETERMINATION. 

Compare the color of the sample, freed from suspended matter, with color 
standards in tubes of clear white glass. 

5 ODOR.— TENTATIVE. 

Shake the vessel containing the sample and note the odor. Heat a portion of the 
sample just to boiling and note the odor. 

g TOTAL SOLIDS.— OFFICLAL. 

Thoroughly shake the vessel containing the sample and pipette 100 cc. of the un- 
filtered water into a weighed platinum dish. If the sample contains much suspended 
matter, shake, pour rapidly into a 100 cc. measuring cylinder, and transfer without 
delay to a weighed platinum dish; evaporate to dryness and heat to constant weight 
at 105°C. In the case of highly mineralized waters it is advisable to weigh again 
after drying at 180°C. 
7 SOLIDS IN SOLUTION.— OFFICIAL. 

Allow the sample to stand until all sediment has settled, and filter if necessary 
to secure a perfectly clear liquid. Occasiona ly a clear filtrate can only be obtained 
by the use of alumina cream but this should be avoided if possible. Evaporate 100- 

35 



36 METHODS OF ANALYSIS [Chap. 

250 cc. to dryness in a weighed platinum dish. Heat to constant weight at 105*0. 
In the case of highly mineralized waters it is advisable to weigh again after drying 
at 180°C. 

8 SUSPENDED MATTER.— OFFICIAL. 

(1) The difference between the values for total solids and dissolved solids rep- 
resents the suspended matter; or, (2) Determine the suspended matter directly by 
filtering a suitable quantity of the water through a tared Gooch crucible, suitably 
prepared, and weighing after drying at 105"'C. 

9 IGNITED RESIDUE.— OFFICIAL. 

Ignite the residue from 6 at a low red heat until the ash is white or nearly so. 
Note any odor or change in color produced during ignition. Record the weight 
of the ignited residue and calculate the loss on ignition. 

FREE AND ALBUMINOID AMMONIA.— OFFICIAL. 

1 REAGENTS. 

(a) Saturated solution of sodium carbonate. 

(b) Ammonia-free water. 

(C) Standard ammonium chlorid solution. — One cc. is equivalent to 0.01 mg. of 
nitrogen in the form of ammonia (NH3). 

(d) Nessler reagent. — Dissolve 50 grams of potassium iodid in a minimum quantity 
of cold water. Add a saturated solution of mercuric chlorid until a slight perma- 
nent precipitate is formed. Add 400 cc. of 50% solution of potassium hydroxid (or 
an equivalent quantity of sodium hydroxid), dilute to 1 liter, allow to settle, and 
decant. 

(e) Alkaline potassium permanganate solution. — Dissolve 200 grams of potassium 
hydroxid and 8 grams of potassium permanganate in water and dilute to 1 liter. 



11 



DETERMINATION. 



Connect a flask of about 1500 cc. capacity with an upright bulb condenser by 
means of a rather large glass tube and a soft rubber stopper or a recently extracted 
cork stopper. Place in the flask 5 cc. of the saturated solution of sodium carbonate 
and 500 cc. of ammonia-free water. Distil into 50 cc. Nessler tubes until no further 
traces of ammonia are indicated on the addition of 2 cc. of the Nessler reagent to 
50 cc. of the distillate. Continue the distillation until the volume of the solution 
in the flask has been reduced to about 200 cc. Cool slightly, add 500 cc. of the water 
under examination, and distil, at the rate of 1 tubeful in 15 minutes, into 50 cc. 
Nessler tubes until ammonia ceases to be given off (4 or 5 tubes are usually sufficient). 
Add 2 cc. of the Nessler reagent to each tube and let stand 10 minutes. Freshly 
prepare in a similar manner other tubes containing known amounts of the standard 
ammonium chlorid, made up to 50 cc. with ammonia-free water, and compare the 
nesslerized distillates with these. Report as milligrams per liter of nitrogen in the 
form of free ammonia (NH3). Cool the flask and add 50 cc. of the alkaline perman- 
ganate recently boiled. Distil, at the rate of 1 tubeful in 15 minutes, into 50 cc. 
Nessler tubes until ammonia ceases to come off. Nesslerize and compare as in the 
determination of free ammonia. Report as milligrams per liter of nitrogen in the 
form of albuminoid ammonia (NHs). 



rV] WATERS 37 

NITROGEN IN THE FORM OF NITRITE— OFFICIAL. 

12 REAGENTS. 

(a) Concentrated hydrochloric acid. — Sp. gr. 1.2. 

(b) Sulphanilic acid solution. — Dissolve 1 gram of sulphanilic acid in 100 cc. of 
hot water. 

(C) Alpha-naphthylamin hydrochlorid solution. — Boil 0.5 gram of the salt with 
100 cc. of water for 10 minutes at constant volume. 

(d) Standard nitrite solution. — Dissolve 1.1 gram of silver nitrite in nitrite-free 
water, precipitate the silver with sodium chlorid solution and dilute to 1 liter, mix 
and allow to settle. Dilute 100 cc. to 1 liter and then 10 cc. of this solution to 1 
liter, using in each case nitrite-free water. Each cc. of the last solution is equivalent 
to 0.0001 mg. of nitrogen as nitrite. 

13 DETEKMINATION. 

Place 100 cc. of the water in a 100 cc. Nessler tube and treat with 1 or 2 drops of 
concentrated hydrochloric acid. Add 1 cc. of the sulphanilic acid, 1 cc. of the alpha- 
naphthylamin hydrochlorid, and thoroughly mix. Set aside for 30 minutes with other 
Nessler tubes containing known amounts of the standard nitrite made up to 100 cc. 
with nitrite-free water, and treated with hydrochloric acid, sulphanilic acid, and 
alpha-naphthylamin hydrochlorid in the manner just described. Determine the 
amount of nitrite by comparing the depth of pink color in the known and unknown 
solutions. Record as nitrogen in the form of nitrite. 

NITROGEN IN THE FORM OF NITRATE. 

Phenoldisulphonic Acid Method. — Official. 

(For water of low chlorin content.) 

14 REAGENTS. 

(a) Phenoldisulphonic acid solution. — Dissolve 25 grams of pure white phenol in 
150 cc. of concentrated sulphuric acid, add 75 cc. of fuming sulphuric acid (13-15% 
SOj) and heat at lOO'C. for 2 hours. 

(b) Standard nitrate solution. — Dissolve 0.722 gram of pure potassium nitrate in 
1 liter of nitrate-free water. Evaporate 50 cc. of this solution to dryness in a porce- 
lain dish ; treat with 2 cc. of the phenoldisulphonic acid solution, rubbing with a glass 
rod to insure intimate contact. Dilute to 500 cc; 1 cc. is equivalent to 0.01 mg. of ni- 
trogen as nitrate. This solution is permanent. Standards for comparison are pre- 
pared by adding ammonium hydroxid to measured volumes of it in 100 cc. Nessler 
tubes. 

(C) Standard silver sulphate solution. — Dissolve 4.3969 grams of silver sulphate, 
free from nitrate, in 1 liter of water; 1 cc. is equivalent to 1 mg. of chlorin. 
(d) Ammonium hydroxid. — Sp. gr. 0.90. 

15 DETERMINATION. 

Take 100 cc. of the sample, or an amount that will contain 0.05 mg. or less of 
nitrogen as nitrate, and add standard silver sulphate, precipitating all but about 
0.5 mg. of the chlorin. Heat to boiling, allow to settle, or add a little alumina cream, 
filter, and wash with small amounts of hot water. Evaporate the filtrate to dryness 
in a porcelain dish on the water bath; when cool, treat with 2 cc. of the phenoldisul- 
phonic acid solution as in 14 (b). Dilute with water and add slowly ammonium hy- 



38 METHODS OF ANALYSIS [Chap. 

droxid until the maximum color is developed. Transfer to a colorimetric cylinder, 
filter if necessary, and compare with the standards in the usual manner. Record as 
nitrogen in the form of nitrate. 

Rediiction Method. — Official. 
(For water of high chlorin content.) 

16 REAGENTS. 

(a) Sodium or potassium hydroxid solution. — Dissolve 250 grams of the purest 
hydroxid obtainable in 1250 cc. of water and boil down to 1 liter. 

(b) Aluminium foil. — Use strips about 10 cm. long, weighing about 0.5 gram. 

1 7 DETERMINATION. 

Place 10 cc.of the sample in a 100 cc. test tube and dilute to exactly 50 cc; add 5 cc. 
of the sodium hydroxid and a strip of the aluminium foil. -Close the mouth of the 
test tube with a rubber stopper carrying a U-shaped glass tube connected with a 
second test tube containing about 50 cc. of ammonia-free water acidified with hydro- 
chloric acid, which sei'ves as a trap to catch any ammonia which might escape. Allow 
to stand at room temperature for 12 hours or more until reduction is complete. Trans- 
fer the contents of the first tube to a Kjeldahl flask and distil. Cool the distillates 
and nesslerize as directed under 1 1 ; also nesslerize the solution in the trap. Record 
as nitrogen in the form of nitrate. 

CHLORIN.— OFFICIAL. 

1 8 REAGENTS. 

(a) N/20 sulphuric acid. 

(b) N/SO sodium carbonate. 

(C) Potassium chr ornate indicator. — Dissolve 5 grams of potassium chromate in 
water, add a solution of silver nitrate until a slight permanent red precipitate is 
produced, filter, and dilute to 100 cc. 

(d ) Standard silver nitrate solution. — Dissolve 4.791 grams of silver nitrate in water 
and dilute to 1 liter; 1 cc. is equivalent to 1 mg. of chlorin. Check by titration against 
a standardized solution of sodium chlorid. 

19 DETERMINATION. 

To 100 cc. of the water add a few drops of phenolphthalein. If a red color appears, 
titrate the carbonates thus indicated to bicarbonates with N/10 or N/20 sulphuric 
acid. If the water is acid to methyl orange, add N/20 sodium carbonate to neutralize 
the acidity. Add 1 cc.of the potassium chromate and titrate with the standard silver 
nitrate. Correct for the amount of silver nitrate necessary to give in 100 cc. of chlorin- 
free water with 1 cc. of the chromate, the shade obtained at the end of the titration 
of the sample. lodids and bromids are not usually found in interfering quantities 
in potable water. However, if they are present make the equivalent correction. 

If chlorids are present in very small quantities concentrate 500 or 1000 cc. in a por- 
celain dish to 100 cc, rub down the sides of the dish carefully, add 1 cc. of the indicator 
and titrate as described above. If sufficient chlorids are present in 100 cc of the water 
to consume more than 25 cc. of the standard silver nitrate, determine by precipita- 
tion in nitric acid solution and weigh the silver chlorid. 



IV] WATERS 39 

OXYGEN REQUIRED. 
Method I. — Official. 

20 REAGENTS. 

(a) Standard potassium permanganate solution. — Dissolve 0.3952 gram of potas- 
sium permanganate in 1 liter of water; each cc. has 0.1 mg. of oxygen available for 
oxidation. 

(b) Standard oxalic acid solution. — Dissolve 0.7875 gram of crystallized oxalic acid 
in 1 liter of water. 

Determine the value of the oxalic acid in terms of the permanganate by boiling 
10 cc. of the oxalic acid and 200 cc. of redistilled water (prepared by treating distilled 
water with alkaline permanganate and distilling) with 10 cc. of sulphuric acid (1 
to 3) and titrating, while still boiling, with the standard permanganate to the appear- 
ance of a pink color. 

21 DETEKMINATION. 

Add 10 cc. of sulphuric acid (1 to 3) to 200 cc. of the water in a porcelain dish and 
heat to boiling. Add from a burette the standard permanganate until the water 
is distinctly red and boil for 10 minutes, adding more of the standard permanganate 
from time to time to maintain the red color. Add 10 cc. of the standard oxalic acid 
and titrate back with the standard permanganate to a pink color. From the total 
number of cc. used of the permanganate subtract the number of cc. equivalent to 10 cc. 
of the oxalic acid. The result gives the number of cc. of the permanganate required 
for 200 cc. of the water. Correct for sulphids, nitrites and ferrous salts, if present, by 
subtracting the number of cc. of the standard permanganate absorbed by another 
200 cc. portion of the sample when treated as above, digesting at room temperature 
for 3 minutes. 

Method II. {Schulze-TrommsdorJ Method.^) — Tentative. 
(To be used when the chlorin content of the sample is high.) 

22 REAGENTS. 

(a) 50% sodium hydroxid solution. 

Other reagents and standard solutions are described under 20. 

23 DETERMINATION. 

Introduce 100 cc. of the water to be examined in a 300 cc. flask, add 0.5 cc. of the 
sodium hydroxid and 10 cc. of the permanganate, boil for 10 minutes, allow to cool to 
50°-60°C. and add 5 cc. of the dilute sulphuric acid and 10 cc. of the standard oxalic 
acid. As soon as the liquid has become perfectly colorless, and while constantly agita- 
ting, cautiously add from a burette, drop by drop, the standard permanganate, until 
the liquid acquires a faint permanent redness. The permanganate required to 
effect this is the quantity required for the decomposition of the organic matter in 
the 100 cc. of water. 

If 100 cc. of the water require more than 4 cc. of the permanganate for the oxidation 
of organic matter, a second determination must be made using more of the per- 
manganate and a correspondingly larger quantity of the sodium hydroxid, as unde- 
composed permanganate remaining after boiling must be at least twice as great as 
the quantity decomposed. 



40 METHODS OF ANALYSIS [Chap. 

DISSOLVED OXYGEN. 

Method I. (Winkler Method as Modified by Drown and Hazen.^) — Tentaiiv2. 
(When less than 0.1 mg. of nitrite nitrogen per liter is present.) 

24 REAGENTS. 

(a) Manganous sulphate solution. — Dissolve 48 grams of manganous sulphate in 
100 cc. of water. 

(b) Sodium hydroxid-potassium iodid solution. — Dissolve 360 grams of sodium 
hydroxid and 100 grams of potassium iodid in 1 liter of water. 

(C) Sulphuric acid. — (Sp. gr. 1.4). Mix equal weights of concentrated sulphuric 
acid and water. 

(d) Standard sodium thiosulphate solution. — Dissolve 6.2 grams of recrystallized 
sodium thiosulphate in 1 liter of water. This gives a N/40 solution, each cc. of which 
is equivalent to0.2mg. of oxygen or 0.1395 cc. of oxygen at 0°C. and 760 mm. pressure. 
This solution should be standardized occasionally against N/40 potassium dichromate. 

(e) Starch indicator. — Mix about 2 grams of clean starch with cold water to a thin 
paste; pour into about 200 cc. of boiling water. Boil for a few minutes. This solu- 
tion should be freshly prepared. 

25 COLLECTION OF SAMPLE. 

Collect the sample in a carefully calibrated glass stoppered bottle, approximately 
250 cc. capacity, by means of an apparatus designed to avoid the entrainment or 
absorption of any oxygen from the atmosphere. Note the temperature. 

26 DETERMINATION. 

Add approximately 2 cc. of the manganous sulphate and 2 cc. of the sodium hydrox- 
id-potassium iodid, delivering both of these solutions beneath the surface of the 
liquid by means of a pipette. Insert the stopper and mix the conteJits of the bottle 
by shaking. Allow the precipitate to settle. Remove the stopper; add about 2 cc. 
of sulphuric acid and mix thoroughly. Rinse the contents of the bottle into a flask; 
titrate with N/40 sodium thiosulphate, using a few cc. of the starch indicator toward 
the end of the titration. Do not add the starch until the color has become a faint 
yellow; titrate until the blue color disappears. Express the results in milligrams 
per liter and in percentage of saturation.' This latter determination is the ratio of 
the amount of gas present to the maximum amount capable of being dissolved by 
distilled water at the same temperature and pressure. 

Method II. (Winkler Method as Modified by Rideal and Stewart.*) — Tentative. 
(When more than 0.1 mg. of nitrite nitrogen per liter is present.) 

27 REAGENTS. 

(a) N/IO potassium permanganate. 

(b) 2% potassium oxalate solution. 
Other reagents are described under 24. 

28 COLLECTION OF SAMPLE. 

Proceed as directed under 25. 



IV] WATERS 41 

29 DETERMINATION. 

Preliminary test. — Determine the amount of the permanganate required to oxi- 
dize the nitrite to nitrate by acidifying a preliminary sample of 50 cc. with 1 cc. of 
the sulphuric acid and adding the permanganate until a slight pink color remains 
after standing 10 minutes. Calculate the amount of the permanganate required for 
a sample collected as described under 25. 

To the sample add 1 cc. of the sulphuric acid and about 0.1 cc. of the perman- 
ganate in excess of the calculated amount required to oxidize the nitrite to nitrate. 
If more than 10 cc. of the permanganate are required add an additional 1 cc. of the 
sulphuric acid. Rotate the bottle and allow to stand for 10 minutes, after which 
destroy any excess of the permanganate by adding from a pipette 0.5-1 cc. of the 
oxalate. Insert the stopper and rotate as before. The color quickly disappears, 
and when decolorized add approximately 2 cc. of the manganous sulphate and 2 cc. 
of the sodium hydroxid-potassium iodid and proceed as in 26. Express the results 
in milligrams per liter and percentage saturation.' 

MINERAL WATER. 

30 SPECIFIC GRAVITY.— TENTATIVE. 

20 °C 

Determine specific gravity at -^q^ by means of a pycnometer. 

31 SOLIDS IN SOLUTION.— OFFICIAL. 

Determine as directed under 7. 

32 IGNITED RESIDUE.— OFFICIAL. 

Determine as directed under 9. 

33 FREE AND ALBUMINOID AMMONIA.— OFFICIAL. 
Determine as directed under 1 1 . 

34 NITROGEN IN THE FORM OF NITRITE.— OFFICIAL. 
Determine as directed under 13. 

35 NITROGEN IN THE FORM OF NITRATE.— OFFICIAL. 
Determine as directed under 15 or 17. 

36 CHLORIN.— OFFICIAL. 
Determine as directed under 19. 

37 HYDROGEN SULPHID.— TENTATIVE. 

Place 0.5-2 cc. of N/100 iodin in a 500 cc. flask and add the water until the color 
of the iodin disappears. Add 5 cc. of the starch indicator and then N/100 iodin until 
a blue color appears. Fill the flask to the mark with water, noting the amount 
added. Subtract the quantity of water, iodin solution, and the starch indicator 
added, to determine the quantity of the water titrated. An excess of iodin is re- 
quired to produce a blue color. A correction is obtained by adding 5 cc. of the 
starch indicator to 500 cc. of water and then adding N/100 iodin until the color 
matches that of the sample under examination. Correct the original titration by 
the amount of iodin used in the blank. 



42 METHODS OF ANALYSIS [Chap. 

38 FREE CARBON DIOXID— TENTATIVE. 

If the water reacts acid to phenolphthalein and alkaline to methyl orange, titrate 
100 cc. with N/20 sodium carbonate (free from bicarbonate) until the solution is 
neutral to phenolphthalein. The number of cc. used multiplied by 1.1 gives the 
milligrams of free carbon dioxid in 100 cc. Express results in milligrams per liter. 

39 CARBONIC AND BICARBONIC ACIDS.— OFFICIAL. 

To 100 cc. of the water add a few drops of phenolphthalein and, if a pink color is 
produced, titrate with N/20 crystallized potassium hydrogen sulphate or sulphuric 
acid, adding a drop every 2 or 3 seconds, until the red color disappears. Multiply 
the burette reading by the factor 3 which gives the milligrams of the carbonic acid 
ion in 100 cc. To the colorless solution from this titration, or to the original solution 
if no color is produced with phenolphthalein, add 1 or 2 drops of methyl orange; con- 
tinue the titration without refilling the burette and note the total reading. If 
carbonic acid is absent, multiply the total burette reading by the factor 3.05, which 
gives the value of the bicarbonic acid ion in milligrams per 100 cc. If carbonic acid is 
present, multiply the reading with phenolphthalein by 2 and subtract from the total 
reading of the burette. Multiply the difference by 3.05, which gives the bicarbonic 
acid ion in milligrams per 100 cc. Express results in milligrams per liter. 

Silica, Iron, Aluminium, Calcium, Strontium and Magnesium. 

40 silica.— official. 

Make a preliminary examination, using 100-250 cc. of water to determine the 
approximate quantity of calcium and magnesium present, in order to ascertain 
the quantity of water to be evaporated for the final analysis. 

Evaporate a quantity, usually 1-5 liters, of the water suSicient to yield 0.1-0.6 
gram of calcium oxid or 0.1-1 gram of magnesium pyrophosphate. Acidify the 
water with hydrochloric acid and evaporate on the water bath to dryness in a plati- 
num dish; continue the drying for about an hour. Thoroughly moisten the residue 
with 5-15 cc. of hydrochloric acid (1 to 1). Allow to stand 10-15 minutes and add 
sufficient water to bring the soluble salts into solution. Heat on the steam bath 
until solution of the salts is effected. Filter to remove most of the silica and wash 
thoroughly with hot water. Evaporate the filtrate to dryness; treat with 5-10 cc. 
of the hydrochloric acid and sufficient water as above. Heat, filter, and wash 
thoroughly with hot water. Designate the filtrate as ^. Transfer the 2 residues to 
a platinum crucible, ignite, heat over a blast lamp and weigh. Moisten the contents 
of the crucible with a few drops of water. Add a few drops of concentrated sulphuric 
acid and a few cc. of hydrofluoric acid and evaporate on the water bath under a good 
hood. Repeat the treatment if all the silica is not volatilized. Dry carefully on a 
hot plate, ignite, heat over a blast lamp, and weigh. The difference between the 
two weights is the weight of the silica. The residue in the crucible consists of alumin- 
ium and iron oxids. The weight of this residue is added to that of the total alumin- 
ium and iron oxids obtained in 41 . (If the above residue weighs more than 0.5 mg., 
barium sulphate may be found here when barium is present in the water. If so, 
make the necessary correction and add to the weight of the total iron and aluminium 
oxids in 41 .) 

41 IRON AND ALUMINIUM.— official. 

Concentrate A , under 40, to about 200 cc. ; while still hot, add ammonium hydroxid 
slowly with constant stirring until alkaline to methyl orange. Boil, filter, and wash 
2 or 3 times with hot water. Dissolve the precipitate in hot hydrochloric acid. 



IV] WATERS 43 

Dilute to approximately 25 cc, boil, and again precipitate with ammonium hydroxid; 
filter, wash thoroughly with hot water, dry, ignite, and weigh as iron and aluminium 
oxids. (In the presence of phosphoric acid, the weight of this residue must be cor- 
rected for the phosphorus pentoxid equivalent to the phosphoric acid found in 51 , 
making due allowance for the difference in the volumes of the water used for these 
determinations.) Designate the filtrate as B. 

IRON. 

42 Colorimetric Method. 

(If the amount of iron is less than 1 mg.) 

Fuse in a platinum crucible the ignited precipitate of iron and aluminium 
oxids with fused potassium hydrogen sulphate, dissolve in water, and precipitate the 
iron and aluminium with ammonium hydroxid. Dissolve the precipitate on the 
filter paper in hydrochloric and nitric acids, dilute the solution, add ammonium 
sulphocyanate solution (1 to 20) and compare the color developed with that of 
calibrated color disks, or standards containing known amounts of iron. 

43 Volumetric Method. 

Fuse in a platinum crucible the residue of iron and aluminium oxids with fused 
potassium hydrogen sulphate. This fusion takes but a few minutes and must not 
be continued beyond the time actually needed. When completed, the crucible 
is set aside and allowed to cool. Add dilute sulphuric acid and heat the crucible 
until the fused mass is dissolved. Evaporate on the water bath as far as possible; 
then heat gradually until copious fumes of sulphuric acid are given off. Dissolve 
in water and allow to stand on the water bath. Cool, transfer to an Erlenmeyer 
flask, and make up to such a volume that the solution does not contain more than 
2.5% of free sulphuric acid. Pass hydrogen sulphid through the solution to reduce 
the iron and precipitate any platinum contaminating the residue from the fusion. 
(Zinc may be used instead of hydrogen sulphid for reducing the iron.) Filter, wash 
and again pass hydrogen sulphid through the solution to be certain that all the iron 
is reduced. Expel the hydrogen sulphid by boiling, at the same time passing a 
current of carbon dioxid through the solution; test the escaping gas with lead acetate 
paper to ascertain the complete removal of hydrogen sulphid. When hydrogen 
sulphid has been removed discontinue boiling and let the flask cool somewhat with- 
out discontinuing the current of carbon dioxid. Titrate the reduced iron with a 
standard permanganate solution (1 cc. equivalent to 1 mg. of Fe) and calculate as 



44 ALUMINIUM.— OFFICIAL. 

In the absence of phosphates, subtract from the weight of iron and aluminium 
oxids, under 41 , the iron, under 42 or 43, calculated to oxid, to obtain the weight of 
aluminium oxid. Calculate to aluminium. 

45 CALCIUM.— OFFICIAL. 

Concentrate B, under 41 , to 150-200 cc. and to this solution, containing not more 
than 0.6 gram of calcium, calculated as calcium oxid, or 1 gram of magnesium, cal- 
culated as magnesium pyrophosphate, add 1-2 grams of oxalic acid and sufficient 
hydrochloric acid to clear the solution. Heat to boiling and neutralize with ammo- 
nium hydroxid, stirring constantly. Add ammonium hydroxid in slight excess and 
allow to stand 3 hours in a warm place. Filter off the supernatant liquid and wash 



44 METHODS OF ANALYSIS [Chap. 

the precipitate once or twice by decantation with 1% ammonium oxalate solution. 
Dissolve the precipitate in hydrochloric acid, dilute to 100-200 cc, add a little 
oxalic acid, and precipitate as above. After standing 3 hours, filter, wash with the 
ammonium oxalate solution as above, dry, ignite, heat over a blast lamp, and weigh 
as calcium and strontium oxids. Subtract from this weight, the weight of strontium 
oxid equivalent to the strontium under 46. The difference is the weight of calcium 
oxid. Calculate to calcium. Designate the filtrate and washings as C 

As a check on the calcium oxid, evaporate to dryness the filtrate from the stron- 
tium nitrate under 46, beginning with "Filter, wash with ether-alcohol mixture, 
etc.," dissolve the calcium nitrate in water, precipitate as oxalate, filter, wash, 
ignite, and weigh as calcium oxid. 

46 STRONTIUM.— TENTATIVE. 

Dissolve the oxids under 45 in dilute nitric acid and test with the spectroscope for 
strontium. If strontium is present, transfer the nitric acid solution to a small 
Erlenmeyer flask. Evaporate nearly to dryness over a low flame and heat in an 
air bath at 150°-160°C. for 1 or 2 hours after the water is evaporated. Break up the 
dried material with a stirring rod, add 10-15 cc. of a mixture of equal parts of absolute 
alcohol and ether to dissolve the calcium nitrate. Cork the flask and allow to stand 
with frequent shaking for 2 hours or longer. Decant the solution through a 5.5 cm. 
filter, preserving the filtrate. Wash the residue several times by decantation with 
small portions of ether-alcohol solution. Dry the residue and the filter paper and 
wash the filter paper repeatedly with small portions of hot water, collecting the 
filtrate in the flask containing the main portion of the strontium nitrate residue. 
Add 1 or 2 drops of dilute nitric acid, evaporate, dry, pulverize, and treat with 
10-15 cc. of ether-alcohol mixture as above. Cork the flask and let stand about 12 
hours with occasional shaking. Filter, wash with ether-alcohol mixture until a few 
drops of the filtrate evaporated on a watch glass leave practically no residue. Dry 
the paper and precipitate. Dissolve the strontium nitrate in a few cc. of hot water. 
Add a few drops of sulphuric acid, then a volume of alcohol equal to the volume of 
the solution and allow to stand 12 hours. Filter, ignite, weigh as strontium sulphate 
and calculate to strontium. Test spectroscopically for absence of calcium. 

47 MAGNESIUM.— OFFICIAL. 

Concentrate C, under 45, to about 200 cc. ; add 2-3 grams of diammonium hydrogen 
phosphate and sufficient hydrochloric acid to clear the solution when the ammonium 
phosphate is all dissolved; disodium hydrogen phosphate or sodium ammonium 
hydrogen phosphate may be used instead of the diammonium hydrogen phosphate. 
When cold, make slightly alkaline with ammonium hydroxid, stirring constantly. 
Add 1-2 cc. excess of ammonium hydroxid and allow to stand about 12 hours. Filter 
off the supernatant liquid and wash 3 or 4 times by decantation with a solution of 
2.5% ammonium hydroxid. Dissolve the precipitate in hydrochloric acid, dilute to 
about 150 cc, add a little diammonium hydrogen phosphate and precipitate with 
ammonium hydroxid as before. Allow to stand 6-12 hours, filter, wash free from 
chlorin, ignite, heat over a blast lamp, and weigh as magnesium pyrophosphate. 
(Cf. II, 16). Calculate to magnesium. 

Sulphuric Acid, Sodium, Potassium and Lithium. 

48 sulphuric acid.— official. 

Make a preliminary examination, using 100-250 cc. of the water to determine the 
approximate quantity of sulphates. The alkali salts present can be approximated 



IV] WATERS 45 

by calculating the amount of sodium necessary to combine with the excess of acids 
(hydrochloric, sulphuric, and bicarbonic) over the calcium and magnesium. 

Take a quantity, usually 1-5 liters, of the water sufficient to yield not more than 
1 gram of barium sulphate and not more than 0.5 gram of mixed chlorids. Acidify 
with hydrochloric acid, evaporate to dryness in a platinum dish and remove silica 
by 2 evaporations as under 40, using not more than 2 cc. of hydrochloric acid (1 to 1) 
for the final solution. Combine the filtrate and washings from the silica determi- 
nations, and concentrate to about 150-200 cc. Heat to boiling and precipitate with 
slight excess of 10% barium chlorid solution, added very slowly and with constant 
stirring. Cover and allow to stand on the steam bath about 12 hours. Filter, wash 
thoroughly the precipitate of barium sulphate with hot water, dry, ignite over a 
Bunsen burner, and weigh. 

If the content of sulphate in the sample is unusually large proceed as far as the 
concentration of the silica filtrates as directed above. Add 50 cc. of concentrated 
hydrochloric acid, heat to boiling and precipitate with barium chlorid solution as 
before. Evaporate to dryness, wash the precipitate repeatedly by decantation and 
filter. Complete the washing of the precipitate; ignite and weigh. Calculate to 
the sulphuric acid ion. Designate the filtrate as E. 

49 SODIUM, POTASSIUM AND LITHIUM.— OFFICIAL. 

Evaporate to dryness £", under 48, in a platinum dish and ignite the residue to faint 
redness to remove all traces of ammonium salts. Dissolve the residue in the dish 
in about 200 cc. of water and precipitate with milk of lime or a solution of barium 
hydroxid. Boil, allow to stand 30 minutes, and filter off the insoluble magnesium 
hydroxid. Thoroughly wash the precipitate with hot water and combine the filtrate 
and washings. If the precipitate of magnesium is large, it is advisable to dissolve 
in a small amount of hydrochloric acid, evaporate to dryness, take up with water, 
and precipitate as before. Concentrate the 2 filtrates and washings to 200-250 cc. 
Add ammonium hydroxid and sufficient ammonium carbonate solution to precipi- 
tate the calcium and barium. Allow to stand on a steam bath 1-2 hours. Filter off 
the supernatant liquid, dissolve the precipitate in hydrochloric acid, reprecipitate as 
above, and wash thoroughly with hot water. Evaporate the combined filtrates and 
washings to dryness and drive off the ammonium salts by gentle heat. Treat the 
residue with water; filter through a small filter, using as little wash water as possible; 
evaporate to a small volume and again precipitate with 1 or 2 drops of ammonium 
hydroxid and 2 or 3 drops of ammonium carbonate and oxalate. If any precipitate 
appears (which is usually not the case) filter and repeat the process. Evaporate the 
filtrate to dryness and drive off all ammonium salts by heating in platinum to faint 
redness. Treat the residue with a little water; filter into a small platinum dish; 
add a few drops of hydrochloric acid and evaporate to dryness. Dry in an oven, 
heat to faint redness, cool in a desiccator, and weigh the combined chlorids of potas- 
sium, sodium, and lithium. Repeat the heating to constant weight, (x). Dissolve 
the mixed chlorids in hot water; filter, and wash. Return the filter paper and residue 
to the dish, dry, ignite, and weigh, (y). The difference between (x) and (y) is the 
weight of the mixed chlorids. 

The determination of lithium is then made according to the method of Gooch.* 
Transfer the combined chlorids to a 50-100 cc. Erlenmeyer flask and evaporate the 
solution nearly, but not quite, to dryness. Add about 30 cc. of redistilled amyl 
alcohol. Connect the flask, the stopper of which carries a thermometer, using a 
condenser if desired, to avoid the escape of the irritating vapor of the amyl alcohol, 
and boil until the temperature rises approximately to the boiling point of amyl alco- 



46 METHODS OF ANALYSIS [Chap. 

hol (130°C.) to remove the water. Cool slightly and add a drop of hydrochloric acid 
to convert small amounts of lithium hydroxid to lithium chlorid. Connect with the 
condenser and repeat the boiling until the temperature reaches the boiling point of 
amyl alcohol to again drive off the water. The content of the flask at this time is 
usually 15-20 cc. Filter through a small paper or a Gooch crucible into a graduated 
cylinder and note the exact quantity of the filtrate, which determines the subsequent 
correction. Wash the precipitate with small quantities of amyl alcohol. Evapo- 
rate the filtrates and washings in a small platinum dish to dryness on the steam bath, 
dissolve the residue in water, and add a few drops of sulphuric acid. Evaporate on 
a steam bath and expel the excess of sulphuric acid by heating gently over a Bunsen 
burner until the carbonaceous matter is completely burned off, repeating the addi- 
tion of a few drops of sulphuric acid if necessary. Cool and weigh the dish and 
contents, (x). Dissolve in a small quantity of hot water, filter through a small 
filter, wash and return filter to dish; ignite and weigh, (y). The difference between 
(x) and (7/) is the weight of impure lithium sulphate. 

The purity of the lithium sulphate should be tested by adding small aniounts of 
ammonium phosphate solution and ammonium hydroxid, which will precipitate any 
magnesium previously present in the lithium sulphate. Any precipitate appearing 
after standing overnight should be collected on a small filter, ignited, weighed as 
magnesium pyrophosphate, calculated to sulphate and subtracted from the weight 
of the impure lithium sulphate. 

From this weight subtract 0.00113 gram of sodium and potassium sulphates for every 
10 cc. of amyl alcohol filtrates, exclusive of the amyl alcohol used in washing the 
residue, on account of the solubility of sodium and potassium chlorids in amyl alco- 
hol. Calculate to lithium from the corrected weight of lithium sulphate. 

Dissolve the mixed chlorids from the flask and filter with hot water, evaporate 
to dryness, ignite gently to remove amyl alcohol, filter, and thoroughly wash; con- 
centrate the filtrates and washings to 25-50 cc. Transfer to a porcelain dish, add 
sufficient platinic chlorid solution [I, 40 (b)] to convert sodium and potassium to 
their respective double chlorids and evaporate to dryness. Treat the residue 
with 80% alcohol, filter, and wash until the excess of platinic chlorid and sodium 
platinic chlorid has been removed. Dry the filter and precipitate, dissolve the 
residue in hot water, and transfer to a weighed platinum dish. Evaporate on the 
steam bath, dry for 30 minutes in the oven at 100°C. and weigh as potassium platinic 
chlorid; calculate to potassium chlorid. To the weight of potassium chlorid add 
0.00051 gram for every 10 cc. of amyl alcohol used in the extraction of the lithium 
chlorid, which corrects for the solubility of the potassium chlorid in amyl alcohol. 
Calculate to potassium. 

The weight of sodium chlorid is found by subtracting the combined corrected 
weights of lithium chlorid and potassium chlorid from the total weight of the 3 
chlorids. Calculate the sodium chlorid to sodium. 

PHOSPHORIC ACID.— OFFICIAL. 

50 REAGENTS. 

The reagents used are described under I, 7. 

51 DETERMINATION. 

Treat 500 cc. of the water, or a larger amount if necessary, with about 10 cc. of 
concentrated nitric acid and evaporate in a porcelain dish nearly to dryness to drive 
off hydrochloric acid. Treat the residue with water and filter, if necessary. Add 
ammonium hydroxid to alkalinity and then just enough nitric acid to restore acidity. 



rV] WATERS 47 

Add some solid ammonium nitrate and heat in the water bath at a temperature of 
45°-50°C. Add the molybdate solution and keep at the above temperature for 30 
minutes. The yellow precipitate formed at this point appears generally only in 
traces; if more than traces are present, filter and wash with cold water until entirely 
free from nitric and molybdic acids. Transfer the precipitate and filter to a beaker, 
add a little water, and beat the paper and contents to a pulp. Dissolve the yellow 
precipitate in a small amount of the standard potassium hydroxid; add phenolphthal- 
ein and titrate with the standard acid. From the data so obtained calculate the 
phosphoric acid ions in the water to milligrams per liter. 

52 Manganese. Iodin, Bromin, Arsenic and Boric Acid. 

Evaporate large quantities of water to dryness, after the addition of small amounts 
of solid sodium carbonate. Boil the residue thus obtained with water, transfer to 
a filter, and wash thoroughly with hot water. Make the alkaline filtrate up to a 
definite volume. 

manganese.— OFFICIAL. 

53 REAGENTS. 

(a) Dilute nitric acid (1 to 1). 

(b) 0.2% silver nitrate solution. 
(C) Ammonium ^persulphate. 

(d) Standard manganous sulphate solution. — Dissolve 0.2877 gram of pure potas- 
sium permanganate in a small amount of water, add an excess of sulphuric acid, 
reduce carefully with oxalic acid and make up to 1 liter. One cc. of this solution is 
equivalent to 0.1 mg. of manganese. 

54 DETERMINATION. 

Dissolve the insoluble residue under 52 in an excess of the dilute nitric acid, evap- 
orate to dryness, treat with water, add about 1 cc. of strong nitric acid and a little 
of the silver nitrate. If a precipitate of silver chlorid appears, add more of the 
silver nitrate until all the chlorin is precipitated. Add an excess of about 10 cc. of 
the silver nitrate for each mg. of manganese present in the sample. Filter, add 
1 gram of ammonium persulphate to the filtrate, and place the beaker or flask con- 
taining the solution on the steam bath until a pink color develops (usually about 20 
minutes). Compare the color developed with standards similarly prepared by treat- 
ing solutions containing known amounts of the standard manganous sulphate with 
nitric acid, silver nitrate, and ammonium persulphate. 

IODIN AND BROMIN.— TENTATIVE. 

55 REAGENTS. 

(a) 10% sodium hydroxid solution. 

(b) Sulphuric acid (1 to 5). 

(C) 2% potassium or sodium nitrite solution. 

(d) Carbon disulphid. — Freshly purified by distillation. 

(e) Chlorin water. — Saturated and freshly prepared. 

56 DETERMINATION. 

Evaporate to dryness an aliquot of the alkaline filtrate under 52, add 2-3 cc. of 
water to dissolve the residue and enough 95% alcohol to make the percentage of 
alcohol about 90. This precipitates the chlorids. Heat to boiling, filter and repeat 
the preceding solution and precipitation once or twice. Add 2 or 3 drops of the 



48 METHODS OF ANALYSIS [Chap. 

sodium hydroxid to the combined alcoholic filtrates and evaporate to dryness. Dis- 
solve this last residue in 2-3 cc. of water and repeat as above described the precipi- 
tation with alcohol, heating, and filtering. Add a drop of the sodium hydroxid to 
this alcoholic filtrate and evaporate to dryness. Dissolve this residue in a little 
water, acidify with the sulphuric acid, using 3 or 4 drops in excess, and transfer to 
a small flask. Add 4 drops of the potassium nitrite and about 5 cc. of the carbon 
disulphid. Shake until all the iodin is extracted, filter off the acid solution from the 
carbon disulphid, retaining the latter in the flask. Wash the flask, filter and con- 
tents with cold water and transfer the carbon disulphid (containing the iodin in 
solution) to a Nessler tube, using approximately 5 cc. of the carbon disulphid. In 
washing the filter make the contents of the tube up to definite volume, usually 12-15 
cc, and compare the color with that of other tubes containing known amounts of 
iodin dissolved in carbon disulphid. Prepare these standard tubes by treating 
measured quantities of a solution of known potassium iodid content as described 
above. Transfer the sample and standards, from which the iodin has been removed, 
severally to small flasks. To the standards add definite measured quantities of a 
bromid solution of known strength, and to each of the flasks containing sample and 
standards add 5 cc. of purified carbon disulphid. Add the saturated chlorin water, 
1 cc. at a time, shaking after each addition until all the bromin is set free. (Avoid 
a large excess of chlorin, since a bromo-chlorid may be formed which spoils the color 
reaction.) Filter off the water solution from the carbon disulphid through a mois- 
tened filter, wash the contents of the filter 2 or 3 times with water, and then transfer 
to a Nessler tube by means of about 1 cc. of carbon disulphid. Repeat this extrac- 
tion of the filtrate twice, using 3 cc. of carbon disulphid each time. The combined 
carbon disulphid extracts usually amount to 11.5-12 cc. Add enough carbon di- 
sulphid to the tubes to bring them to a definite volume, usually 12-15 cc, and com- 
pare the sample with the standards. In some cases when using this method near its 
upper limit the amounts of carbon disulphid recommended do not extract all the 
bromin. In these cases, make 1 or 2 extra extractions with carbon disulphid, trans- 
fer the extracts to another tube, and compare the color with some of the lower 
standards and add the readings thus obtained to the others. 

Results closely approximating the true values for iodin and bromin can be ob- 
tained on most samples by omitting the extractions, with alcohol given above and 
by comparing the color of the carbon disulphid solutions directly in the extraction 
flasks, thus shortening the method. 

ARSENIC— OFFICIAL. 

57 REAGENTS. 

(a) Zinc, arsenic-free. 

(b) Sulphuric acid {1 to 5), arsenic-free. 

(C) Standard arsenious oxid solution. — Dissolve 0.0132 gram of pure arsenious 
oxid in 100 cc. of water containing about 50 mg. of sodium carbonate. One cc. of 
this solution is equivalent to 0.1 mg. of As. 

58 DETERMINATION. 

Evaporate to dryness an aliquot of the alkaline filtrate under 52. Acidify with 
the sulphuric acid and subject to the action of the zinc and the sulphuric acid in a 
Marsh-Berzelius apparatus. Compare the mirror obtained with a mirror prepared 
from an arsenious oxid solution of known strength. Calculate to the arsenic acid 
ion. 



IV] WATERS 49 

BORIC ACID.— OFFICIAL. 

(Glassware containing boron must not be used in this determination.) 

59 DETERMINATION. 

Qualitative test. — Evaporate to dryness a part of the alkaline filtrate under 52, 
treat with 1-2 cc. of water, and slightly acidify with dilute hydrochloric acid (1 to 1). 
Add about 25 cc. of 95% alcohol, boil, filter, and repeat the extraction of the residue. 
Make the filtrate slightly alkaline with sodium hydroxid solution and evaporate 
to dryness. Add a little water, slightly acidify with dilute hydrochloric acid, and 
place a strip of turmeric paper in the liquid. Evaporate to dryness on the steam 
bath and continue the heating until the turmeric paper is dry. If boric acid is 
present the turmeric paper takes on a cherry-red color. As a confirmatory test, 
apply a drop of dilute ammonium hydroxid to the reddened paper, and a dark 
olive color will be due to boric acid. 

Quantitative test. — It is not usually necessary to determine boric acid quantita- 
tively. However, if it is necessary, the Gooch method^ is used. 

30 METHOD OF REPORTING RESXTLTS.— TENTATIVE. 

Report the bases and acids as positive and negative ions in milligrams per liter, 
except in the case of silica, which report as such without considering how much is 
present as the silicic acid ion and how much as free silica. Report iron and alumin- 
ium together when present in unimportant quantities, and in calculations consider 
it as iron. When iron and aluminium are present in larger quantities make the 
separation and report each separately. 

In calculating the hypothetical combinations of acid and basic ions join sodium 
to nitrous, nitric, metaboric and arsenic acids; potassium to iodin and bromin; 
calcium to phosphoric acid. Assign the residual basic ions in the following order; 
ammonium, lithium, potassium, sodium, magnesium, calcium, strontium, manganese, 
iron and aluminium — to the residual acid ions in the following order: Chlorin, 
sulphuric acid ion, carbonic acid ion, and bicarbonic acid ion. In case the bicar- 
bonic acid ion is not present in a sufficient quantity to join with all the calcium, 
the residual calcium is joined to silica to form calcium silicate, and manganese, iron, 
and aluminium are calculated to the oxids MnsO^, FeoOs, and AI2O3, respectively. 

INDUSTRIAL WATER. 

61 SOLIDS IN SOLUTION.— OFFICLAL. 
Determine as directed under 7. 

62 CHLORIN.— OFFICIAL. 
Determine as directed under 19. 

63 COMBINED CARBONIC AND BICARBONIC ACIDS.— OFFICIAL. 
Determine as directed under 39. 

64 NITRATES.— OFFICIAL. 
Determine as directed under 1 5 or 1 7. 

65 SILICA.— OFFICIAL. 

Determine as directed under 40. Generally one evaporation with hydrochloric 
acid for removal of silica is sufficient. 



50 METHODS OF ANALYSIS [Chap. 

66 IRON AND ALUMINIUM.— OFFICIAL. 
Determine as directed under 41. 

67 CALCIUM.— OFFICIAL. 

If no phosphoric acid is present, concentrate the filtrate from the determination 
of iron and precipitate with ammonium hydroxid and oxalate as directed under 45. 
Usually one precipitation is sufficient. 

68 MAGNESIUM.— OFFICIAL. 

Determine as directed under 47. 

69 SULPHURIC ACID AND ALKALIES.— OFFICIAL. 

Follow the methods described under 48 and 49. Generally, however, for tech- 
nical purposes it is sufficiently accurate to determine the acids and the bases, 
except sodium and potassium, and then to calculate the excess of acid over basic 
ions to the sodium salt, and state the alkali thus found as sodium and potassium by 
difference. 

70 TEMPORARY HARDNESS.'— TENTATIVE. 

The difference between the alkalinity after boiling, 74, and the alkalinity before 
boiling, 72, is the temporary hardness in parts per million of calcium carbonate. 

ALBJVLINITY— Before Boiling. 

71 REAGENTS. 

(a) N /50 sulphuric acid. 

(b) Erythrosin indicator. — Dissolve 0.1 gram of the sodium salt in 1 liter of water. 
(C) Chloroform. — Neutral to erythrosin. 

72 DETERMINATION. 

Measure 100 cc. of the water into a 250 cc. white, glass-stoppered bottle, add 2.5 cc. 
of the erythrosin and 5 cc. of the chloroform, add N/50 sulphuric acid in small quanti- 
ties, shaking the bottle vigorously after each addition of the acid. The rose color 
gradually disappears and is finally discharged by 1 or 2 drops of the acid. A white 
paper held back of the bottle facilitates the detection of the end point. Multiply 
the number of cc. of N/50 sulphuric acid used by 10 to obtain the number of parts per 
million of alkalinity in terms of calcium carbonate. 

ALKALINITY-After Boiling. 

73 REAGENTS. 

Described under 71 . 

74 DETERMINATION. 

Boil 100 cc. of the water in a porcelain dish gently for 30 minutes. Cool, transfer 
to a 100 cc. volumetric flask and fill to the mark with recently boiled and cooled 
water. Filter through a dry paper and determine the alkalinity of the filtrate as 
directed under 72, making the proper calculation for the aliquot employed and cal- 
culating in terms of calcium carbonate the parts per million of alkalinity after 
boiling. 



IV] WATERS 51 

TOTAL HARDNESS.8— TENTATIVE. 

75 REAGENTS. 

(a) Soda reagent. — Prepare a N/10 alkali solution, using equal parts of sodium 
hydroxid and sodium carbonate. Standardize the solution by titration against 
N/20 sulphuric acid, using erythrosin as indicator. 

76 DETERMINATION. 

Add sufficient N/20 sulphuric acid to 200 cc. of the sample to neutralize the alkalin- 
ity, the amount required for this purpose being calculated from the results obtained 
as directed under 72. Concentrate to 100 cc, add 25 cc. of the soda reagent^ and 
again boil down to 100 cc, using a porcelain, silver, or platinum dish. Cool, rinse 
into a 200 cc. volumetric flask and dilute to 200 cc. with freshly boiled and cooled 
water. Filter through a dry paper, reject the first 50 cc. of the filtrate, and titrate 
100 cc. of the filtrate, using N/20 sulphuric acid and chloroform with erythrosin as 
indicator, as directed under 72. Calculate the total hardness by the following 
formula: H = 12.5 (S-2N) in which 

H = total hardness expressed as parts per million of calcium carbonate. 

S = number of cc. of N/20 sulphuric acid equivalent to the 25 cc. of the soda 
reagent used. 

N = number of cc of N/20 sulphuric acid used in titrating back the excess of 
the soda reagent. 

77 PERMANENT OR NON-CARBONATE HARDNESS.— TENTATIVE. 

The difference between the alkalinity before boiling 72 and the total hardness 76 
is the permanent or non-carbonate hardness expressed as parts per million of cal- 
cium carbonate. 

IRRIGATING WATER. 

78 GENERAL METHODS.— OFFICIAL. 

Determine the solids in solution, chlorin, carbonic and bicarbonic acidSj sulphuric 
acid, calcium and magnesium as directed under 7, 19, 39, 48, 45, and 47 respec- 
tively. To make the hypothetical combination, calculate calcium and magnesium 
to the acid ions in the following order: bicarbonic, sulphuric and chlorin. Then 
calculate the remaining acid ions, including carbonic, to the corresponding salts of 
sodium. 

BLACK ALKALI.— OFFICIAL. 

79 REAGENTS. 

(a) N/50 sodium carbonate. — One cc of this solution is equivalent to 0.00106 
gram of sodium carbonate. 

(b) N'/SO sulphuric acid. — One cc. of this solution is equivalent to 0.0010 gram of 
calcium carbonate or 0.00136 gram of calcium sulphate. 

(C) Erythrosin indicator. — Dissolve 0.25 gram of the sodium salt in 1 liter of water. 
(d) Chloroform. — Neutral to erythrosin. 

80 DETERMINATION. 

Transfer 200 cc. of the water to a platinum or silver dish, add 60-100 cc. of N/50 
sodium carbonate, according to the amount of soluble salts of calcium and magnesium 
present, and evaporate to dryness. Rub up the residue with carbon dioxid-free 
water. 



52 METHODS OF ANALYSIS 

For this purpose distilled water should be vigorously boiled until approximately 
one third of the original volume is evaporated, then cooled and stoppered. An 
ordinary laboratory wash bottle should not be used to transfer the residue, as the 
carbon dioxid from the breath of the operator is sufficient to vitiate the results. 

Transfer to a 100 cc. graduated flask, make up to the mark, shake thoroughly, and 
allow to stand until clear (12-15 hours). Remove 50 cc. of the clear, supernatant 
liquid, equivalent to one half of the original quantity of water and sodium carbonate 
added, and transfer to a stoppered titrating bottle, of 250 cc. capacity, of clear glass 
without any tinge of pink. Add 5 cc. of the chloroform and 1 cc. of the erythrosin 
and titrate with the standard acid until the color disappears. Shake the solution 
vigorously after each addition of the acid; the chloroform produces a milky appear- 
ance which makes the reading of the end point sharp and certain. 

(1) If less sulphuric acid is required than is equivalent to one half of the sodium 
carbonate added, due to some of the sodium carbonate reacting with soluble salts of 
calcium and magnesium, the solution originally contained no black alkali in excess 
but rather an excess of the so-called permanent or non-carbonate hardness. It is 
customary to express the hardness in terms of calcium carbonate or calcium sul- 
phate. With irrigating waters the latter form is to be preferred. Therefore, the 
difference between the number of cc. of the sulphuric acid required and one half of 
the number of cc. of the sodium carbonate added multiplied by the factor 0.00136 
gives the equivalent of calcium sulphate in 100 cc. of the water. 

(2) If more sulphuric acid is required than that equivalent to one half of the 
sodium carbonate added, black alkali was originally present in the solution and the 
difference in cc. multiplied by the factor 0.00106 gives the black alkali in terms of 
sodium carbonate in 100 cc. of water. 

BIBLIOGRAPHY. 

* Fresenius. Quantitative Chemical Analysis. Revised and amplified trans- 
lation of the 6th German ed., 1906, 2 : 204. 

» Ber., 1888, 21: 2843; Rept. Mass. State Board of Health, 1890, 2: 722. 
» J. Am. Chem. Soc, 1911, 33: 362; Standard Methods of Water Analysis. Am. 
Pub. H. Assoc, 2nd ed., 1912, pp. 61 and 62. 

* Sutton. Volumetric Analysis, 10th ed., p. 303; Analyst, 1901, 26: 141. 

* Am. Chem. J. 1887, 9: 33; U. S. Geol. Surv. Bull. 422, 175. 
« Am. Chem. J. 1887, 9 : 23. 

^ Standard Methods of Water Analysis. Am. Pub. H. Assoc, 2nd ed., 1912, pp. 
36 and 37. 

* Ibid, pp. 40 and 41. 



V. TANNING MATERIALS.— TENTATIVE. 

EXTRACTS. 

1 PREPARATION OF SOLUTION. 

(a) Solid extracts. — Grind solid extracts in a large porcelain mortar, so that the 
material will pass through a 10 mesh sieve, mix thoroughly and weigh out a quantity 
containing 3.75-4.25 grams of tannin. This should be done as rapidly as possible to 
avoid change in moisture content. Pour into 100 cc. of water at 85°C., place on a 
steam bath and stir until a homogeneous solution is obtained. Transfer to a 1 liter 
flask with 800 cc. of water at 85°C. Cool rapidly to 20°C. and make up to 1 liter. 

(b) Fluid extracts. — Allow fluid extracts to come to room temperature and mix 
thoroughly. Weigh out rapidly a quantity containing 3.75-4.25 grams of tannin. 
Dissolve by washing into a 1 liter flask with 900 cc. of water at 85°C. Cool rapidly 
to 20°C. and make up to 1 liter at 20°C. 

After the preparation of the solutions, proceed at once with the analysis. 

2 TOTAL SOLIDS. 

Thoroughly mix the prepared solution, pipette at once 100 cc. into a tared flat- 
bottomed glass dish, 2|-3 inches in diameter, and (1) evaporate and dry for 16 hours 
in a combined evaporator and dryer' at 98°-100°C.; or, (2) after evaporating on the 
steam bath, dry for 12 hours on the bottom of a water oven at 98°-100°C. Remove 
immediately to desiccators containing sulphuric acid (place no more than 2 dishes in 
1 desiccator) and weigh rapidly when cooled. Calculate the percentage of total 
solids. 

SOLUBLE SOLIDS. 

3 PREPARATION OF FILTER. 

The kaolin used should be neutral to phenolphthalein and should not yield more 
than 1 mg. of soluble solids per 100 cc. of filtrate of a 1% suspension after an hour's 
digestion at 20°C. Dry on a water bath and preserve in a tightly stoppered bottle. 

Add about 75 cc. of the solution, as prepared under 1 , to 1 gram of the kaolin in a 
beaker. Stir and pour immediately into a single, 15 cm. No. 590, S. & S. folded 
filter. Return the filtrate to the paper when approximately 25 cc. have run through, 
repeat the operation for an hour, thus transferring all the kaolin to the paper. At 
the end of an hour, discard the solution on the filter by siphoning it off, disturbing 
the kaolin as little as possible. 

4 DETERMINATION. 

Bring about 150 cc. of the original solution, as prepared under 1 , to exactly 20''C. 
Fill the filter, prepared as under 3, with this solution and discard the filtrate until 
it runs through clear. Keep the filter full, the temperature of the filtering solution 
at 20°-25°C., and the funnel and receiving vessel covered. Pipette at once 100 cc. of 
the clear filtrate into a tared dish, evaporate and dry as directed under 2. Calculate 
the percentage of soluble solids. 

53 



54 METHODS OF ANALYSIS [Chap. 

5 INSOLUBLE SOLIDS. 

The difference between the percentage of the total solids and the percentage of 
soluble solids is the percentage of the substance insoluble in water at 20°-25°C. 

NONTANNINS. 

6 REAGENTS. 

Hide powder. — This should be of woolly texture, well delimed, and 10 grams of the 
water-free powder should require 12-13 cc. of N/10 sodium hydroxid to neutralize it. 

Calculate the amount of air-dry hide powder v.'hic-h will be required for the number 
of determinations to be made, on a basis of 13 grams of air-dry hide powder for 
each determination. Increase this calculated amount by 35 grams of dry hide 
powder to provide a sufficient amount for all the determinations. 

Thoroughly digest the total amount of hide powder with 10 times its weight of 
water. Then for each gram of the hide powder, so digested, add 1 cc. of 3% chrome 
alum solution; and either agitate frequently for several hours and let stand overnight 
or agitate in some form of mechanical shaker for an hour. Transfer to a strong 
linen filter and squeeze thoroughly. Remove from the filter and digest for 15 minutes 
Math a quantity of water equivalent to 15 times the weight of the dry hide powder 
employed. Filter and squeeze to approximately 73% of water, using a press if 
necessary. Very strong pressure is required to reduce the water content below 
70%. Repeat the digestion and filtration 3 times. Determine moisture in 20 grams 
of the squeezed hide powder as directed under 2. 

7 DETERMINATION. 

Place 46 grams of the wet hide powder in a suitable container of about 300 cc. 
capacity, add 200 cc. of the tanning solution, as prepared under 1 , and shake for 10 
minutes in a mechanical shaker. Squeeze immediately through linen, add 2 grams 
of kaolin, as used under 3, to the filtrate which contains the nontannins, stir, and 
filter through a single, folded 18.5 cm. filter paper (No. IF. Swedish, preferred), 
refiltering until the filtrate is clear. The filtrate should give no precipitate with a 
gelatin-salt solution (1% gelatin and 10% salt). Pipette 100 cc. of the filtrate into 
a tared dish and evaporate as directed under 2. Correct the weight of the nontannin 
residue for the dilution caused by the water retained in the wet hide powder. Cal- 
culate the percentage of nontannins. 

8 TANNIN, 

The difference between the percentage of the soluble solids and the percentage 
of nontannins is the percentage of tannin. 

DETECTION OF SULPHITE-CELLULOSE. 

9 REAGENTS. 

Sulphile-cellulose solution. — Dissolve 0.5 gram of the total solids, derived from 
sulphite cellulose, in 1 liter of water and add sufficient tanning material, free from 
sulphite-cellulose, to give a concentration of 3.75-4.25 grams of tannin per liter. 

10 DETERMINATION. 

Place 5 cc. of the tanning solution, prepared as under 1, in a test tube; add 0.5 cc. 
of anilin and shake well; then add 2 cc. of concentrated hydrochloric acid and mix 
again. Compare the precipitate formed with that produced when the above sul- 



V] TANNING MATERIALS 55 

phite-cellulose solution is similarly treated. Sulphite-cellulose is held to be present, 
in the predetermined absence of the synthetic tanning material, Neradol-D, if the 
precipitates are approximately equivalent in amount. 

LIQUORS. 

11 PREPARATION OF SOLUTION. 

Dilute the liquor with water at room temperature to contain approximately 0.7 
gram of solids in 100 cc. of solution. If the liquor does not give a proper solution 
with water at room temperature, it may be diluted with water at 80°C., and then 
cooled rapidly to 20°C. 

12 TOTAL SOLIDS. 
Proceed as directed under 2. 

13 SOLUBLE SOLIDS. 
Proceed as directed under 4. 

14 NONTANNINS. 

Proceed as directed under 7, using the amount of wet chromed hide powder which 
will give the ratio between the tannin and hide powder shown in the following table: 



TANNIN RANGE PER 
100 CC. 


DRr HIDE POWDER 
PER 200 CC. 


gravi 

0.35—0.45 
0.25—0.35 
0.15—0.25 
0.00—0.15 


grams 

9.0—11.0 
6.5— 9.0 
4.0— 6.5 
0.0— 4.0 



TOTAL ACIDITY. 
15 REAGENTS. 

(a) Hematin solution. — Digest 0.5 gram of hematin in 100 cc. of cold neutral 95% 
alcohol. 

(b) Gelatin solution. — Dissolve 10 grams of gelatin in hot water, cool, add 25 cc. of 
95% alcohol and dilute. If the gelatin solution is acid or alkaline, neutralize with 
N/10 sodium hydroxid or N/10 acetic acid, respectively, using hematin solution as 
indicator and make up to 1 liter. 

(C) Kaolin. — Digest with dilute hydrochloric acid; wash and dry as under 3. 
(d) N/10 sodium hydroxid. 



16 



DETERMINATION. 



Add 25 CC. of the gelatin solution to 25 cc. of the tanning liquor in a stoppered 
cylinder, dilute with water to 250 cc, add 15 grams of the kaolin and shake vigorously. 
Allow to settle for at least 15 minutes, remove 30 cc. of the supernatant liquid, dilute 
with 50 cc. of water and titrate with N/10 sodium hydroxid, using the hematin solu- 
tion as indicator. Each cc. of N/10 sodium hydroxid is equivalent to 0.2 % acid, 
calculated as acetic, in the liquor. 



56 



METHODS OF ANALYSIS 



[Chap. 



RAW AND SPENT MATERIALS. 

(Under raw materials are included woods, barks, leaves, etc.) 

1 7 MOISTURE IN SAMPLE AS RECEIVED. 

Cut or break up large pieces and mix the sample rapidly to avoid change in mois- 
ture content. Dry as directed under 2, a suitable weighed quantity, dependent upon 
the physical condition and moisture content of the sample. 

18 PREPARATION OF SAMPLE. 

Dry the remainder of the sample at a temperature not above 60°C. and grind to 
pass through a 20 mesh sieve. 

19 MOISTURE IN PREPARED SAMPLE. 

Take 10 grams of the sample prepared in 1 8, dry as directed under 2, and calculate 
all results to an "as received", "air dry", or "moisture free" basis as desired. 

20 EXTRACTION. 




FIG. 4. METAL EXTRACTOR USED FOR EXTRACTING TANNING MATERIALS. 

(For spent materials approximate the following quantities as closely as possible.) 

Place a quantity of the dried sample, containing 3.75-4.25 grams of tannin, n a 
beaker and wet thoroughly with hot water. Place a perforated porcelain plate in 
a tin-lined copper extractor of the general form shown in Fig. 4, and on the plate 
place a layer of cotton and wet thoroughly with water. Connect the extractor with 
an 800 cc. Erlenmeyer flask (G), open the stock-cock (E) and close the outlets (C) 
and (D). Pour into the extractor the material to be extracted, washing it into the 
extractor with hot water. Return the percolate through the extractor until it is 
practically clear. Place a layer of cotton on top of the material. Close the stop- 
cock (E), connect with an 800 cc. Erlenmeyer flask containing about 650 cc. of water, 
connect (D) by a delivery tube with a liter graduated collecting flask, return the 
total percolate to the extractor and connect by means of the metal cap {B) with a 
block tin condenser (A) in such a way that the condensate will drip upon the layer 
of cotton. Boil the water in the flask, and collect 400-500 cc. of percolate from the 
side tube (D). Open the stop-cock (E) and close the side tube (D), add water to the 
flask (G), if necessary, until it contains about 200 cc. Continue the extraction with 
water at steam heat, allowing the percolate to run back into the boiling flask. Re- 



V] TANNING MATERIALS 57 

peat with 2 successive portions (150-250 cc. each) of water for a total of 14 hours, 
heating at such a rate that approximately 330 cc. of water will be condensed per 
hour. Combine all the extracts in the graduated liter flask in which the first per- 
colate was received. Heat to 80°C., cool, and make up to the mark. 

21 ANALYSIS OF THE EXTRACT. 

Proceed as directed under 2—8, inclusive. If more dilute solutions than the 
directions specify are employed in the determination of nontannins, the amount of 
hide powder used is reduced, as directed under 14. 

BIBLIOGRAPHY. 
1 J. Am. Leather Chem. Assoc, 1906, 1: 32. 



JOURNAL 

OF THE 

ASSOCIATION OF OFFICIAL 
AGRICULTURAL CHEMISTS 



^:T^m^ 



Vol. II MAY 15, 1916 Nd. 1 




BOARD OF EDITORS 
C. L. Alsbkrg, Chairman 
R. E. DooLiTTLE J. P. Street 

E. F. Ladd L. L. Van Sltke 

PART II 

Report of Committee on Editing Methods of Analysis 
Leathers 

Insecticides and Fungicides 
Foods and Feeding Stuff's 
Saccharine Products 
Food Preservatives 



PUBLISHED QUARTERLY BY 

THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS 

WILLIAMS & WILKINS COMPANY 

BALTIMORE, U. S. A. 

THE CAMBRIDGE UNIVERSITY PRESS 
FETTER LANE, LONDON, E. C. 



Eutered as seoond-dass matter August 25, 1915. at the Post-Office at Baltimoro, Maryland, under the Act of August 24, 1912 
Copyright 19tfl by Association of Official Aipicultural Chemists 



VI. LEATHERS— TENTATIVE. 
VEGETABLE TANNED LEATHER. 

1 PREPARATION OF SAMPLE. 

Grind the sample, without undue heating, and pass through a 10 mesh sieve. The 
ground sample must not contain hard lumps. Plane heavily greased leathers (con- 
taining more than 20 % fat) into very thin shavings. Spread out the prepared sample 
and allow it to return to atmospheric moisture condition; mix thoroughly, and 
place in tightly covered containers. 

2 MOISTURE. 

Place 10 grams of the sample, as prepared under 1 , in a tared, wide, shallow, weigh- 
ing bottle (or a similar dish which can be covered tightly), and dry in a water oven 
for 15 hours at 98'-100°C. Cover the weighing bottle, cool in a desiccator containing 
sulphuric acid, and weigh. The moisture present in the leather as received may be 
determined by cutting it quickly into small pieces and drying without grinding as 
directed above. 

3 TOTAL ASH. 

Incinerate slowly 5 grams of the sample, as prepared under 1 , at a dull red heat. 
If difficulty is experienced in burning off the carbon, leach the residue with hot 
water, filter on an ashless filter, dry and ignite the filter and residue, add the filtrate, 
evaporate to dryness and ignite. Cool in a desiccator containing sulphuric acid and 
weigh. 

The ash may be examined for acids and bases by any suitable method. Alumin- 
ium, magnesium, sodium, barium, calcium and lead are the bases, and hydrochloric 
and sulphuric acids are the acids which it may be necessary to determine. 

4 INSOLUBLE ASH. 

Incinerate slowly the residue from the extraction of water-soluble material, ob- 
tained in 6 or 7, until all the carbon is burned off, cool in a desiccator containing 
sulphuric acid and weigh. 

5 FATS. 

Place, without packing, 15 grams of the leather, as prepared under 1 , in a Soxhlet 
or Johnson extractor with a layer of fat-free cotton above and below the sample. 
Extract 8-10 hours with petroleum ether distilling between 50° and 80°C. Heavily 
greased leathers (containing 15% or more fat) will require the maximum time. Re- 
move the receiving flask, evaporate the petroleum ether on the steam bath and dry 
the fat residue for 3 hours in a water oven at 98°-100°C., cool in a desiccator and 
weigh. Repeat the drying in the water oven for periods of 1-1^ hours, cooling and 
weighing as before, until no further loss in weight occurs. Retain the leather 
residue from the fat extraction for the extraction of water-soluble material in 6 or 7. 

EXTRACTION OF WATER-SOLUBLE MATERIAL. 

6 Method I. 

Evaporate the petroleum ether from the fat-free leather, obtained under 5, and 
moisten thoroughly with from 100-150 cc. of water. Place a layer of cotton in the 

59 



60 METHODS OF ANALYSIS [Chap. 

bottom of a Soxiilet extractor designed for making extractions at temperatures be- 
low 100°C. 

An extractor of this kind is furnished with a water jacket surrounding that por- 
tion of the apparatus containing the sample but does not enclose the side tube which 
carries the hot vapors to the condenser. 

Transfer the moistened fat-free leather to the extractor, and cover this with 
another layer of cotton to avoid siphoning off solid particles. Maintain the tempera- 
ture of the jacket surrounding the Soxhlet at 50°C. (1) Pour 200 cc. of water (in- 
cluding that used in moistening the leather) into the Soxhlet and allow it to siphon 
into the flask below, then heat and extract for an hour. Remove the flame and trans- 
fer the extract to a liter graduated flask. Then add water and continue the ex- 
traction as directed below, removing and transferring the extract to the liter 
flask before each fresh addition of water. 

(2) Add 175 cc. of water and extract for 2 hours. 

(3) Add 175 cc. of water and extract for 3 hours. 

(4) Add 175 cc. of water and extract for 4 hours. 

(5) Add 175 cc. of water and extract for 4 hours. 

Transfer the last portion of the extract to the graduated flask. This gives 14 
hours' extraction and an extract which does not exceed 1 liter in volume. Dilute to 1 
liter at room temperature and mix thoroughly. 

7 Method 11. 

(This method is the same in principle as the official method of the American Leather 

Chemists Association. i) 

Digest overnight 30 grams of the fat-free leather, obtained under 5, in approxi- 
mately 200 cc. of water. Transfer the leather and extract to a percolator. Continue 
the extraction by percolating with water at 50°C. Collect 2 liters of percolate, 
regulating the flow of water at such a rate that 2 liters will be collected in 3 hours. 
Dilute to volume at room temperature and mix thoroughly. 

To the extract, prepared according to 6 or 7, add a few drops of toluol to prevent 
fermentation of sugars, and reserve for the determination of glucose, total solids, 
soluble solids, and nontannins. 

GLUCOSE. 

8 PREPARATION OF SOLUTION. 

To 200 CC. of the leather extract, as prepared under 6 or 7, add 25 cc. of a saturated 
solution of normal lead acetate, mix thoroughly, and filter at once through a dry, 
plaited paper, returning the first portions of the filtrate to the filter until the fil- 
trate becomes clear. Keep the containers and the funnel covered during these opera- 
tions. Without waiting for the entire filtrate to run through add 10-12 grams 
of solid potassium oxalate, shake frequently during 15-20 minutes and filter through 
a dry, plaited paper returning the first runnings to the filter until the filtrate runs 
clear. Pipette 150 cc. of the last filtrate into a 600 cc. Erlenmeyer flask, add 5 cc. of 
concentrated hydrochloric acid and boil under a reflux condenser for 2 hours. Cool, 
neutralize with solid sodium carbonate, using a little phenolphthalein as indicator, 
transfer to a 200 cc. volumetric flask and complete to volume with water. Filter 
through a double filter, and return the first runnings until the filtrate becomes 
perfectly clear. Determine the dextrose in the filtrate immediately. 



VI] LEATHERS 61 

9 DETERMINATION. 

Determine dextrose in 50 cc. of the solution, as prepared under 8, equivalent to 
0.5 gram of leather, according to VIII, 25 and express the result as glucose. 

I TOTAL SOLIDS. 

Determine as directed under V, 2. 

I I SOLUBLE SOLIDS. 
Determine as directed under V, 4. 

1 2 NONTANNINS. 
Determine as directed under V, 7. 

13 SOLUBLE TANNIN. 

The difference between the percentage of the soluble solids and the corrected 
nontannins is the percentage of tannin. 

1 4 NITROGEN. 
Determine as directed under I, 21 . 

15 HIDE SUBSTANCE. 

Multiply the percentage of nitrogen by 5.62. The result will be the percentage 
of hide substance present. 

1 6 COMBINED TANNIN. 

Deduct the sum of the percentages of moisture, under 2, insoluble ash, under 4, 
soluble solids, under 1 1 , and hide substance, under 1 5, from 100. The result will 
be the percentage of combined tannin. 

BIBLIOGRAPHY. 
» J. Am. Leather Chem. Assn., 1915, 10: 122. 



VII. INSECTICIDES AND FUNGICIDES. 
GENERAL METHOD. 

1 PREPARATION OF SAMPLE.— TENTATIVE. 

Mix thoroughly all samples before analysis. Make water-soluble arsenic deter- 
minations on samples as received without further pulverization or drying. In 
the case of lye, sodium cyanid or potassium cyanid, weigh large quantities in weigh- 
ing bottles and analyze aliquots of the aqueous solutions. 

PARIS GREEN. 

2 MOISTURE.— TENTATIVE. 

Dry 2 grams at 105''-110°C. for 5 hours and express the loss in weight as moisture. 

TOTAL ARSENIC— OFFICIAL. 
(Arsenic, present as arsenate, is titrated as arsenious oxid.) 

3 REAGENTS. 

(a) Starch indicator . — Mix about 0.5 gram of finely powdered potato starch with 
cold water to a thin paste; pour into about 100 cc. of boiling water. 

(b) Standard arsenious oxid solution. — Dissolve 2 grams of pure arsenious oxid 
in a beaker by boiling with about 150-200 cc. of water containing 10 cc. of concen- 
trated sulphuric acid, cool, transfer to a 500 cc. graduated flask and dilute to the 
mark. 

(C) Standard iodin solution. — Prepare an approximately N/20 solution as fol- 
lows: Mix intimately 6.35 grams of pure iodin with twice its weight of pure potas- 
sium iodid. Dissolve in a small amount of water, filter and dilute the filtrate to 

1 liter in a liter graduated flask. Standardize against (b) as follows: Pipette 50 
cc. of the arsenious oxid into an Erlenmeyer flask, dilute to about 400 cc, neutralize 
with sodium bicarbonate, add 4-5 grams in excess, and add the standard iodin solu- 
tion from a burette, shaking the flask continuously, until the yellow color disap- 
pears slowly from the solution, then add 5 cc. of the starch indicator and continue 
adding the iodin solution, drop by drop, until a permanent blue color is obtained. 
Calculate the value of the standard iodin solution in terms of arsenious oxid (AsaOs) 
and arsenic oxid (As20s). Occasionally restandardize the iodin against freshly 
prepared arsenious oxid solution. 

4 APPARATUS. 

The apparatus used is shown in Fig. 5. The distillation flask rests on a metal 
gauze which fits over a circular hole in a heavy sheet of asbestos board. The first 

2 Erlenmeyer flasks are of 500 and 1000 cc. capacity and contain about 40 and 100 
cc. of water, respectively. Both of these flasks should be placed in a pan and kept 
surrounded with cracked ice and water. The third flask, containing a small amount 
of water, is used as a trap. 

63 



64 



METHODS OF ANALYSIS 



[Chap. 



DETERMINATION. 

Weigh an amount of the sample equal to the arsenious oxid equivalent of 250 
cc. of the standard iodin solution, and wash into the distillation flask by means of 
100 cc. of concentrated hydrochloric acid (sp. gr. 1.19). Add 5 grams of cuprous 
chlorid (CU2CI2) and distil. 

When the volume in the distillation flask is reduced to about 40 cc, add 50 cc. 
of concentrated hydrochloric acid by means of the dropping funnel and continue 
the distillation until 200 cc. of the acid distillate have passed over. Then wash 
down the condenser and all the connecting tubes carefully, transfer these washings 
and the contents of the 3 Erlenmeyer flasks to a liter graduated flask and dilute 
to the mark. Mix thoroughly, pipette 400 cc. into an Erlenmeyer flask and nearly 
neutralize with a saturated solution of sodium or potassium hydroxid, using a few 
drops of phenolphthalein as an indicator, keeping the solution well cooled. 

Continue as directed under 3 (C) beginning with "neutralize with sodium bicar- 
bonate." The number of cc. of iodin used in this titration represents directly 
the total per cent of arsenic in the sample expressed as arsenious oxid (AS2O3). 




FIG. 5. APPARATUS FOR DISTILLATION OF ARSENIC CHLORID. 



TOTAL ARSENIOUS OXID. 

(The following methods determine arsenic, and antimony if present, as the -ous 
oxids, AS2O3 and SbaOs, respectively. Ferrous and cuprous salts vitiate the results.) 

Method I. 
C. C. Hedges Method,^ Modified.^— Tentative. 

6 REAGENTS. 

The reagents and solutions used are described under 3. 

7 DETERMINATION. 

Weigh an amount of the sample equal to the arsenious oxid equivalent of 100 cc. 
of the standard iodin solution, wash into an Erlenmeyer flask with 10-15 cc. of dilute 
hydrochloric acid (1 to 1), followed by about 100 cc. of water, and heat on the steam- 
bath to complete solution, at a temperature not exceeding 60°C. Cool, neutralize 



VII] INSECTICIDES AND FUNGICIDES 65 

with sodium bicarbonate, add 4-5 grams in excess, and then sufficient 25% ammonium 
chlorid solution to dissolve the precipitated copper. Dilute somewhat and titrate 
as directed under 3 (C) . A correction must be applied for the amount of iodin solu- 
tion necessary to produce a blue color with starch in the presence of copper (using 
an equivalent weight of copper sulphate) . The corrected number of cc. of the stand- 
ard iodin solution used represents directly the per cent of arsenious oxid (AszOs) 
in the sample. 

Method II. 

8 CM. Smith Method,^ Modified. —Tentative. 

Proceed as directed in 7, using dilute sulphuric acid (1 to 4) instead of dilute 
hydrochloric. The solution in this case may be heated to boiling. 

SODIUM ACETATE-SOLUBLE ARSENIOUS OXID.*— TENTATIVE. 

9 REAGENTS . 

(a) Sodium acetate solution. — Prepare a solution containing 12.5 grams of the 
crystallized salt (CH3COONa3H20) in each 25 cc. 
The other reagents are described under 3. 

10 DETERMINATION. 

Place 1 gram of the sample in a 100 cc. flask and boil for 5 minutes with 25 cc. of 
the sodium acetate. Dilute to the mark, shake, and pass through a dry filter 
paper. Titrate an aliquot of this filtrate as directed under 3 (C). Calculate the 
amount of arsenious oxid (AS2O3) present and express the result as per cent of 
sodium acetate-soluble arsenious oxid. 

WATER-SOLUBLE ARSENIOUS OXID.— TENTATIVE. 

11 REAGENTS. 

Described under 3. 



12 



DETERMINATION . 



To 1 gram of the sample in a liter Florence flask add 1 liter of recently boiled water 
which has been cooled to exactly 32°C. Stopper the flask and place in a water 
bath kept at 32°C. by means of a thermostat. Digest for 24 hours, shaking hourly 
for 8 hours during this period. Filter through a dry filter and titrate 250 cc. of the 
filtrate as directed under 3 (C) . Correct for the amount of the standard iodin neces- 
sary to produce the same color, using the same reagents and volmne. Calculate 
the amount of arsenious oxid (AS2O3) present and express the result as per cent of 
water-soluble arsenious oxid. 

TOTAL COPPER OXID. 

13 Electrolytic Method. — Official. 

Treat 2 grams of the sample in a beaker with 100 cc. of water and about 2 grams 
of sodium hydroxid and boil thoroughly until all the copper is precipitated as cu- 
prous oxid. Filter, wash well with hot water, dissolve the precipitate in hot dilute 
nitric acid, cool, transfer to a 250 cc. graduated flask and dilute to the mark. (1) 
Use 50-100 cc. of this solution for the electrolytic determination of copper as directed 
under VIII, 33 and calculate to per cent cupric oxid; or, (2) Electrolyze the aliquot in 
a weighed 150 cc. platinum dish, using a rotating spiral anode and a current of about 



-#. 



66 METHODS OF ANALYSIS [Chap. 

3 amperes. After all the copper is deposited (requiring about 30 minutes), wash 
the deposit with water by siphoning, then rinse with alcohol, dry for a few min- 
utes in an oven, weigh and calculate to per cent cupric oxid. 

14 Thiosulphate Method.^ — Official. 

Determine copper in another aliquot of the nitric acid solution of copper oxid, 
under 13, by titrating with N/20 thiosulphate solution, as directed under VIII, 29, 
and calculate to per cent cupric oxid. 

LONDON PURPLE. 

1 5 MOISTURE.— TENTATIVE. 

Determined as directed under 2. 

TOTAL ARSENIOUS OXID.'— OFFICIAL. 

16 REAGENTS. 

Described under 3. 

17 DETERMINATION. 

Dissolve 2 grams of the sample in a mixture of about 80 cc. of water and 20 cc. 
of concentrated hydrochloric acid at a temperature of 60°-70°C.; filter and wash 
until the combined filtrate and washings measure 250 cc. Treat 100 cc. of this solu- 
tion with sodium bicarbonate in excess, transfer to a 500 cc. volumetric flask and 
make up to the mark, adding a few drops of ether to destroy the bubbles. Mix 
thoroughly and pass through a dry filter. Titrate 250 cc. of the filtrate as directed 
under 3 (C) and calculate the per cent of arsenious oxid. 

TOTAL ARSENIC OXID.'— OFFICIAL. 

18 REAGENTS. 

The reagents and solutions used are described under 3. 

19 DETERMINATION. 

Boil, on a hot plate or over a low flame, 2 grams of the sample with 5 cc. of con- 
centrated nitric acid and 20 cc. of concentrated sulphuric acid in a Kjeldahl diges- 
tion flask or a covered casserole. After 10-15 minutes add fuming nitric acid or 
powdered sodium nitrate, in small quantities at a time, until all organic matter 
is destroyed and the solution is practically colorless. Cool, add about 50 cc. of 
water to decompose any nitro-sulphuric acid formed) and heat again until all 
nitric acid fumes are expelled. Cool, transfer to a 250 cc. volumetric flask, make 
up to the mark with water, mix thoroughly, and filter through a dry filter. 

Transfer 50 cc. of this filtrate to a 400 cc. Erlenmeyer flask, dilute with water 
to 100 cc, add 1 gram of potassium iodid,^ heat to boiling and evaporate to about 
40 cc. not less). Cool, dilute to 150-200 cc, and remove the excess of iodin with 
N/20 sodium thiosulphate. In case the solution is slightly colored from organic 
matter or from any cause other than free iodin, add the thiosulphate until it is nearly 
colorless, then a few drops of the starch indicator, and continue adding the thio- 
sulphate slowly until the blue color just disappears. Continue at once as directed 
under 3 C) beginning with "neutralize with sodium bicarbonate." Subtract from 
this reading the number of cc. of the standard iodin solution corresponding to the 
arsenious oxid obtained in 17. Calculate the per cent of arsenic oxid in the sample. 



VII] INSECTICIDES AND FUNGICIDES 67 

20 WATER-SOLUBLE ARSENIOUS OXID.— TENTATIVE. 

Proceed as directed under 12, slightly acidifying the aliquot employed with 
hydrochloric acid before adding the excess of sodium bicarbonate. 

WATER-SOLUBLE ARSENIC OXID.— TENTATIVE. 

21 REAGENTS. 

The solutions and reagents used are described under 3. 

22 DETERMINATION. 

Transfer an aliquot, 250 cc, of the water extract, from 20, to a casserole, add 5 
cc. of concentrated sulphuric acid, evaporate to a small volume and heat on a hot 
plate till white fumes of sulphuric acid appear. Cover the casserole and add 1-2 
cc. of fuming nitric acid and again heat till the appearance of white fumes. Cool, 
add a little water and, in order to expel the last traces of nitric acid, once more 
evaporate till white fumes appear. Cool, dilute to about 100 cc. with water, add 
1 gram of potassium iodid* and sufficient sulphuric acid to make the total amount 
present about 5 cc. Boil until the volume is reduced to about 40 cc. Cool, dilute 
to about 200 cc, remove the excess iodin with N/20 sodium thiosulphate and pro- 
ceed as directed under 3 (C) beginning with "neutralize with sodium bicarbonate." 
Correct for the amount of the standard iodin solution necessary to produce the 
same color, using the same reagents and volume. Subtract from the corrected titra- 
tion reading the number of cc. of the standard iodin solution corresponding to the 
arsenious oxid, obtained in 20. Calculate the per cent of arsenic oxid present. 

LEAD ARSENATE. 

23 MOISTURE.— TENTATIVE. 

(a) Powder. — Dry 2 grams to constant weight at lOS^-llO" C. and report the 
loss in weight as moisture. 

(b) Paste. — Proceed as under (a), using 50 grams. 

Grind the dry sample to a fine powder, mix well, transfer a small portion to a 
sample bottle and again dry for 1-2 hours at 105''-110°C., and use this anhydrous 
material for the determination of total lead oxid and total arsenic. 

TOTAL LEAD OXID. 

24 Method I. ^—Official. 

Heat, on a hot plate, 0.6906 gram of the dry powdered sample with about 25 cc. 
of dilute nitric acid (1 to 4) in a 600 cc. beaker. If necessary, remove any insoluble 
residue by filtration. Dilute to at least 400 cc, heat nearly to boiling, add am- 
monium hydroxid to incipient precipitation, then dilute nitric acid ^1 to 10) to re- 
dissolve the precipitate, adding 1-2 cc in excess. Pipette into this solution, kept 
almost boiling, 50 cc. of a hot 10% potassium chromate solution, stirring constantly. 
Decant while hot through a weighed Gooch, previously heated at 140''-150°C., wash 
several times by decantation and then on the filter with boiling water until the 
washings are colorless. Dry the lead chromate at HC-loO'C. to constant weight. 
The weight of lead chromate multiplied by 100 gives the per cent of lead monoxid 
(PbO) in the dried sample. 

The lead chromate precipitate may contain a small amount of lead arsenate which 
causes slightly high results. This error rarely amounts to more than 0.1-0.2%. 



68 METHODS OF ANALYSIS [Chap. 

Method II ?°— Tentative. 
(Not applicable in the presence of calcium.) 

25 REAGENT. 

Acidified alcohol .—Mix water 100 parts; 95% alcohol 200 parts; and concentrated 
sulphuric acid 3 parts by volume. 

26 DETEKMINATION. 

Heat, on a hot plate, 0.7360 gram of the dry powdered sample with about 25 cc. 
of dilute nitric acid (1 to 4) in a porcelain evaporating dish or casserole. Remove 
any insoluble residue by filtration. Add 3 cc. of concentrated sulphuric acid and 
evaporate on the hot plate to the appearance of white fumes. It is important that 
all nitric acid be expelled. Cool, add 50 cc. of water and about 100 cc. of 95% alco- 
hol, let stand several hours (preferably over-night) and filter through a weighed 
Gooch crucible, previously washed with water, the acidified alcohol and 95% alco- 
hol, and dried at200°C. Wash the precipitate of lead sulphate in the crucible about 
10 times with the acidified alcohol and then with 95% alcohol until free from sul- 
phuric acid. Dry at 200°C. to constant weight, keeping the crucible covered to pre- 
vent loss by spattering. The weight of the lead sulphate multiplied by 100 gives 
the per cent of lead monoxid (PbO) in the dried sample. 

TOTAL ARSENIC. 

27 Method I. ^—Official. 

Proceed as directed under 5, using an amount of the sample equal to the arsenic 
oxid equivalent of 500 cc. of the standard iodin solution and titrating a 200 cc. aliquot 
of the distillate. The number of cc. used of the standard iodin solution represents 
directly the total per cent of arsenic in the sample expressed as arsenic oxid (AS2O6) . 

Method 11.^^— Official. 
(Not applicable in the presence of antimony.) 

28 REAGENTS. 

The reagents and solutions used are described under 3. 

29 DETERMINATION. 

Dissolve an amount of the powdered sample equal to the arsenic oxid equivalent 
of 400 cc. of the standard iodin solution, in dilute nitric acid in a porcelain casserole 
or evaporating dish. Add 5 cc. of concentrated sulphuric acid and heat on the 
hot plate to copious evolution of white fumes. Wash into a 200 cc. graduated flask 
with water, cool, make up to the mark and filter through a dry filter. Transfer 
100 cc. of the filtrate to an Erlenmeyer flask and proceed as directed under 22, 
beginning with -'add 1 gram of potassium iodid," to "Subtract from the corrected 
titration reading." The number of cc. of the standard iodin solution used, divided 
by 2, represents directly the per cent of total arsenic in the sample expressed as 
arsenic oxid (AszOs). 

WATER-SOLUBLE ARSENIC OXID.— TENTATIVE. 

30 REAGENTS. 

The reagents and solutions used are described under 3. 



Vn] INSECTICIDES AND FUNGICIDES 69 



31 



DETERMINATION . 



Treat 2 grams of the original sample, if in the form of a powder, or 4 grams, if 
a paste, as directed under 12 through "Filter through a dry filter." 

Place 250-500 cc. of the clear filtrate in an Erlenmeyer flask, add 3 cc. of con- 
centrated sulphuric acid and evaporate on a hot plate. When the volume is re- 
duced to about 100 cc, proceed as directed under 22 to "Subtract from the cor- 
rected titration reading." Calculate and report as per cent of water-soluble arsenic 
oxid (AS2O6). 

CALCIUM ARSENATE. 

32 TOTAL ARSENIC— OFFICIAL. 

Proceed as directed under 5, using an amount of the powdered sample equal 
to the arsenic oxid equivalent of 250 cc. of the standard iodin solution. 

The number of cc. of the standard iodin solution used represents directly the 
total per cent of arsenic in the sample expressed as arsenic oxid (AS2O6) . 

ZINC ARSENITE. 

33 TOTAL ARSENIC.i— OFFICIAL. 

Proceed as directed under 5, using an amount of the powdered sample equal to 
the arsenious oxid equivalent of 500 cc. of the standard iodin solution and titrating 
a 200 cc. aliquot of the distillate. The number of cc. of the standard iodin solution 
used represents directly the per cent of total arsenic in the sample expressed as ar- 
senious oxid (AS2O3). 

34 TOTAL ARSENIOUS OXIB.— TENTATIVE. 
Proceed as directed under 7 or 8. 

COPPER CARBONATE. 

35 COPPER OXID.— OFFICIAL. 

Dissolve a weighed quantity of the substance in dilute nitric acid and deter- 
mine copper as directed under 13 or 14. 

BORDEAUX MIXTURE. 

36 MOISTURE.— OFFICIAL. 

(a) Powder. — Dry 2 grams to constant weight at 105°-110°C. and express the 
loss in weight as moisture. 

(b) Paste. — Heat about 100 grams in an oven at 90-100°C. until dry enough to 
powder readily, and note the loss in weight. Powder this partially dried sample, 
and determine the remaining moisture in 2 grams as under (a). Determine car- 
bon dioxid, as directed under 38, both in the original paste and in this partially 
dried sample. Calculate the total moisture by the following formula: 

M = a + (100-a) (b + c) - d in which 

M = per cent total moisture in original paste; 

a = per cent loss in weight of original paste during first drying; 

b = per cent loss in weight of partially dried paste during second drying; 

c = per cent carbon dioxid remaining in partially dried paste after first 

drying; 
d = per cent total carbon dioxid in original paste. 



70 METHODS OF ANALYSIS [Chap. 

CARBON DIOXID."— OFFICIAL. 

37 APPARATUS. 

This consists of a 200 cc. Erlenmeyer flask closed with a 2-hoIed stopper; one of 
these holes is fitted with a dropping funnel the stem of which extends almost to the 
bottom of the flask; the outlet of a condenser, which is inclined upward at an angle 
of 30° from the horizontal, passes downward through the other hole. The upper 
end of the condenser is connected with a calcium chlorid tube which in turn is 
connected with a double U-tube filled in the middle with pumice fragments, pre- 
viously saturated with copper sulphate solution and subsequently dehydrated, 
and with calcium chlorid at either end. Then follow 2 weighed U-tubes for absorb- 
ing the carbon dioxid, the first filled with porous soda-lime, and the second, one 
third with soda-lime and two thirds with calcium chlorid, the latter reagent being 
placed at the exit end of the train. A Geissler bulb, partly filled with sulphuric 
acid, is attached to the last U-tube to show the rate of gas flow. An aspirator is 
connected with the Geissler bulb to draw air through the apparatus. An absorp- 
tion tower filled with soda-lime is connected with the mouth of the dropping funnel 
to remove carbon dioxid from the air entering the apparatus. 

38 DETERMINATION. 

Weigh 2 grams of the powder or 10 grams of the paste into the Erlenmeyer flask, 
add about 20 cc. of water, attach the flask to the apparatus omittipg the 2 weighed 
U-tubes, and draw carbon dioxid-free air through the apparatus until the original 
air is displaced. Then attach the weighed U-tubes in the position as described in 37, 
close the stop-cock of the dropping funnel, fill half full with dilute hydrochloric 
acid (1 to 1), reconnect with the soda-lime tower, and allow the acid to flow into 
the Erlenmeyer flask, slowly if there is much carbon dioxid, rapidly if there is 
little. When eff'ervescence diminishes, place a low Bunsen flame under the flask and 
start a flow of water through the condenser, a slow current of air being allowed to 
flow through the apparatus at the same time. Maintain a steady but quiet ebulli- 
tion, and a slow air current through the apparatus. Boil for a few minutes after 
the water has begun to condense in the condenser, then remove the flame and con- 
tinue the aspiration of air at the rate of about 2 bubbles per second until the 
apparatus is cool. Disconnect the tared absorption tubes, cool in the balance case 
and weigh. The increase in weight is due to carbon dioxid. 

COPPER. 

39 Electrolytic Method. — Official. 

Dissolve 2 grams of the dry powdered sample in 20 cc. of water and 5 cc. of con- 
centrated nitric acid, dilute to 100 cc, wash into a weighed 150 cc. platinum dish, 
and electrolyze, using a rotating spiral anode and a current of about 3 amperes. 
After all the copper is deposited vrequiring about 30 minutes), wash the deposit 
with water by siphoning, then rinse with alcohol, dry for a few minutes in an oven, 
and weigh. Calculate the per cent of copper in the sample. 

40 Thiosulphate Method. — Official. 

Dissolve 2 grams of the dry powdered sample in about 50 cc. of 10% nitric acid, 
add ammonium hydroxid solution in excess and heat; then, without removing the 
precipitate which is formed, boil off the excess of ammonia, add 5-10 cc. of acetic 
acid, cool, add 10 cc. of 30% potassium iodid solution, and titrate as directed under 

VIII, 29. 



Vn] INSECTICIDES AND FUNGICIDES 71 

BORDEAUX MIXTURE WITH PARIS GREEN. 

41 MOISTURE.— OFFICIAL. 
Proceed as directed under 36. 

42 CARBON DIOXID.— OFFICIAL. 
Proceed as directed under 38. 

COPPER. 

43 Method I. — Tentative. 

Dissolve 2 grams of the dry powdered sample in a few cc. of strong nitric acid, 
add 25 cc. of a 3% solution of hydrogen peroxid and warm for 5-10 minutes. Make 
slightly alkaline with ammonium hydroxid and then slightly acid again with dilute 
nitric acid. Transfer to a weighed 150 cc. platinum dish, add 15-20 cc. of hydrogen 
peroxid, dilute to 100 cc. and electrolyze, using a rotating spiral anode and a cur- 
rent not exceeding 2 amperes. After the electrolysis has proceeded for about 20 
minutes, add to the electrolyte 0.5 gram of ferric sulphate dissolved in a few cc. 
of water together with a drop or two of nitric acid. After all the copper is deposited, 
wash the deposit with water by siphoning, then rinse with alcohol, dry for a few 
minutes in an oven, weigh and calculate the per cent of copper. (Do not pass the 
current for more than 5-10 minutes after all the copper has been deposited without 
adding more ferric sulphate solution.) 

44 Method n.— Tentative. 

Treat 1 gram of the dry powdered sample with 20 cc. of water and 5-6 cc. of con- 
centrated nitric acid, heat to boiling, cool, and add a slight excess of concentrated 
ammonium hydroxid. Wash the solution and precipitate into a weighed platinum 
dish of about 150 cc. capacity, and electrolyze, using a rotating anode and a cur- 
rent of about 4 amperes and 3-4 volts for about 90 minutes (or until all the copper 
is deposited). Wash the deposit by siphoning until the deposit is clean, being care- 
ful not to use too much wash water. Dissolve the copper in 5 cc. of concentrated 
nitric acid, dilute to 100 cc. and electrolyze as before, except that all the copper 
will be deposited in 30 minutes. Wash the deposit with water by siphoning, then 
rinse with alcohol, dry for a minute or so in an oven, weigh and calculate the per 
cent of copper. 

45 TOTAL ARSENIC.i— OFFICIAL. 

Proceed as directed under 5, using an amount of the dry powdered sample equal 
to the arsenious oxid equivalent of 500 cc. of the standard iodin solution. The num- 
ber of cc. of the standard iodin solution used, divided by 2, represents directly the 
per cent of total arsenic in the sample expressed as arsenious oxid (AS2O3) . 

TOTAL ARSENIOUS OXID. 

46 Method I.— Tentative. 

Proceed as directed under 7, using an amount of the dry, powdered sample equal 
to the arsenious oxid equivalent of 200 cc. of the standard iodin solution. Before 
titrating, all the copper must be in solution. The corrected number of cc. of the 
standard iodin solution used, divided by 2, represents directly the per cent of total 
arsenious oxid (AS2O3) in the sample. 



72 METHODS OF ANALYSIS [Chap. 

47 Method II. — Tentative. 
Proceed as directed under 8. 

48 WATER-SOLUBLE ARSENIOUS OXID.— TENTATIVE. 

Proceed as directed under 20, using 2 grams of the sample. 

BORDEAUX MIXTURE WITH LEAD ARSENATE. 

49 MOISTURE.— OFFICIAL. 
Proceed as directed under 36. 

50 CARBON DIOXID.— OFFICIAL. 

Proceed as directed under 38. 

51 COPPER.— TENTATIVE. 

Proceed as directed under 44. 

52 LEAD OXID.s— TENTATIVE. 

Dissolve the lead peroxid (which will contain a little arsenic) from the anodes 
used in the copper electrolysis, under 51 , by means of dilute nitric acid and a little 
hydrogen peroxid, and add to this solution the washings from both electrolyses 
of copper. Add ammonium chlorid to dissolve any lead sulphate which may have 
precipitated out and make the solution up to 1 liter. Concentrate a 500 cc. aliquot 
of this solution to about 300 cc. (all hydrogen peroxid must be expelled from the 
solution), transfer to a 400 cc. beaker and precipitate the lead as lead chromate 
as directed under 24. 

53 TOTAL ARSENIC.i— OFFICIAL. 

Proceed as directed under 5, using an amount of the dry, powdered sample equal 
to the arsenic oxid equivalent of 500 cc. of the standard iodin solution. The num- 
ber of cc. of the standard iodin solution used, divided by 2, represents directly the 
per cent of total arsenic in the sample expressed as arsenic oxid (AS2O6) . 

54 WATER-SOLUBLE ARSENIC OXID.— TENTATIVE. 

Proceed as directed under 31 . 

SODIUM AND POTASSIUM CYANIDS. 

55 CYANOGEN."— OFFICIAL. 

Weigh about 10 grams of the sample in a weighing bottle, dissolve in water, and 
make up to volume in a liter graduated flask. To a 50 cc. aliquot add N/20 silver 
nitrate, drop by drop, stirring constantly, until 1 drop produces a permanent tur- 
bidity. In calculating the results, 1 equivalent of silver is equal to 2 equivalents 
of cyanogen, according to the following equation: 

2NaCN + AgN03 = NaCNAgCN + NaNO, 

Reserve the titrated solution for the determination of chlorin under 56. 



Vn] INSECTICIDES AND FUNGICIDES 73 

55 CHLORIN.H— OFFICIAL. 

After completion of the titration for cyanogen, as directed under 55, add a few 
cc. of 10% potassium chromate solution as indicator and titrate with N/20 silver 
nitrate until the appearance of the red-brown color of silver chromate. 

The first titration with silver nitrate represents the cyanogen present according 
to the equation above. The second titration represents the cyanogen and chlorin 
according to the following equation : NaCNAgCN + NaCl + 2AgN03 = 2NaN03 + 
2AgCN + AgCl. Therefore the second minus the first reading represents the chlorin 
present in terms of silver nitrate. 

SOAP. 

MOISTURE. 

57 Modified Method of Benedickt and Lewkowitsch.^^ — Tentative. 

Weigh about 5 grams of the sample in a tared, 100 cc. beaker, in which is pre- 
viously placed a 5 inch layer of recently ignited, dry sand, and a small glass rod; 
if the soap is hard, cut off the soap in very thin strips. Add 25 cc. of alcohol, 
or more if necessary, and dissolve on the water bath, stirring constantly. Evapo- 
rate the alcohol, heat in an oven at 110°C. until the soap is nearly dry, and weigh, 
then dry again for 30 minutes and weigh. Continue this alternate drying and 
weighing until the weight changes only a few milligrams during the course of 30 
minutes' drying. 

58 POTASSIUM AND SODIUM.''— TENTATIVE. 

Dissolve about 5 grams of the soap in water; decompose with hydrochloric acid, 
filter off the water and wash the fat with cold water. Determine both potassium 
and sodium in the filtrate as directed under II, 21 . 

SODA LYE. 

59 CARBONATE AND HYDROXID.n— OFFICIAL. 

Weigh about 10 grams of the sample from the weighing bottle, dissolve in car- 
bon dioxid-free water and make up to a definite volume. Titrate an aliquot of this 
solution with N/2 hydrochloric acid, using methyl orange as an indicator, and note 
the total alkalinity thus found. Transfer an equal aliquot to a graduated flask 
and add enough barium chlorid solution to precipitate all the carbonate, avoiding 
any unnecessary excess. Dilute to the mark with carbon dioxid-free water, stopper, 
shake, and set aside. When the liquid becomes clear, pipette off one half and ti- 
trate with N/2 hydrochloric acid, using phenolphthalein as an indicator. The 
number of cc. of N/2 acid, required for this titration, multiplied by 2 gives the num- 
ber of cc. of N/2 acid required to neutralize the sodium hydroxid present in the 
original aliquot. The difference between this figure and the number of cc. of N/2 
hydrochloric acid required for the total akalinity represents the number of cc. of 
N/2 acid required to neutralize the sodium carbonate present in the aliquot. Cal- 
culate the percentages of sodium carbonate and hydroxid present in the sample. 

TOBACCO AND TOBACCO EXTRACT. 

NICOTIN. 

Kissling Method. — Official. 

60 REAGENTS. 

(a) Alcoholic sodium hydroxid solution. — Dissolve 6 grams of sodium hydroxid 
in 40 cc. of water and 60 cc. of 90% alcohol. 



74 METHODS OF ANALYSIS [Chap. 

(b) 0.4% sodium hydroxid solution. 

(C) N /lO sulphuric acid. — One cc. is equivalent to 16.22 mg. of nicotin. 

(d) Phenacetolin solution. — Prepare a 0.5% alcoholic solution. 

(e) Cochineal solution. — Prepare as directed under I, 16 (k). 



61 



DETERMINATION . 



Weigh 5-6 grams of tobacco extract, or 20 grams of finely powdered tobacco 
which has been previously dried at 60°C. if necessary, into a small beaker. Add 
10 cc. of the alcoholic sodium hydroxid and follow, in the case of tobacco extract, 
with enough pure powdered calcium carbonate to form a moist but not lumpy mass. 
Mix thoroughly, transfer to a Soxhlet extractor and exhaust for about 5 hours with 
ether. Evaporate the ether at a low temperature, and take up the residue with 50 
cc. of the 0.4% sodium hydroxid solution. Transfer this residue by means of water 
to a 500 cc. Kjeldahl flask, and distil with steam, passing the distillate through a 
condenser cooled by a rapidly flowing current of water. Use a 3-bend outflow tube, 
and, to prevent bumping and frothing, add a few pieces of pumice, and a small piece 
of paraffin. Distil till all the nicotin has passed over, the distillate usually varying 
from 400-500 cc. When completed, only about 15 cc. of the liquid should remain in 
the flask. Titrate the distillate with N/10 sulphuric acid, using the phenacetolin 
or cochineal solution as indicator. 

Silicotungstic Acid Method.^^ — Official. 

62 REAGENTS. 

(a) Silicotungstic acid solution. — Prepare a 12% solution of the silicotungstic 
acid having the following formula: 4H20.Si02.12W03.22H20. 

(b) Sodium or potassium hydroxid solution {1 to 2). 
(C) Dilute hydrochloric acid {1 to 4). 



63 



DETERMINATION . 



Weigh such an amount of the preparation as will contain preferably between 0.1 
and 1.0 gram of nicotin (if the sample contains very little nicotin, about 0.1%, do 
not increase the amount to the point where it interferes with the distillation) ; wash 
with water into aSOOcc. round-bottomed distillation flask; add a little paraffin to pre- 
vent frothing, a few small pieces of pumice and a slight excess of the sodium or 
potassium hydroxid, using phenolphthalein as an indicator. Distil rapidly in a 
current of steam through a well-cooled condenser, connected by means of an adapter 
with a suitable flask containing 10 cc. of the dilute hydrochloric acid. When distil- 
lation is well under way, heat the distillation flask to reduce the volume of the liquid 
as far as practicable without bumping or undue separation of insoluble matter. Dis- 
til until a few cc. of the distillate show no cloud or opalescence when treated with a 
drop of the silicotungstic acid and a drop of the dilute hydrochloric acid. Confirm 
the alkalinity of the residue in the distillation flask with phenolphthalein solution. 
Make up the distillate, which may amount to 1000-1500 cc, to a convenient volume (the 
solution may be concentrated on the steam bath without loss of nicotin), mix well 
and pass through a large dry filter if not clear. Test a portion with methyl orange 
to assure its acidity. Pipette an aliquot, containing about 0.1 gram of nicotin, into 
a beaker lif the samples contain very small amounts of nicotin, an aliquot contain- 
ing as little as 0.01 gram of nicotin may be used), add. to each 100 cc. of liquid 3 cc. 
of the dilute hydrochloric acid, or more if the necessity is indicated by the test with 
methyl orange, and add 1 cc. of the silicotungstic acid for each 0.01 gram of nico- 



VII] INSECTICIDES AND FUNGICIDES 75 

tin supposed to be present. Stir thoroughly and let stand overnight. Before filter- 
ing, stir the precipitate to see that it settles quickly and is in crystalline form; then 
filter on an ashless filter paper, and wash with cold dilute hydrochloric acid (1 to 
1000). Transfer the paper and precipitate to a weighed platinum crucible, dry 
carefully, and ignite until all carbon is destroyed. Finally heat over a Teclu or 
Meker burner for not more than 10 minutes. The weight of the residue multiplied 
by 0.114 gives the weight of nicotin present in the aliquot. 

FORMALDEHYDE SOLUTIONS. 
FORMALDEHYDE. 

Hydrogen Peroxid Method. ^^ — Official. 

64 REAGENTS. 

(a) N/1 sulphuric acid. 

(b) N/l sodium hydroxid. — One cc. is equivalent to 30.02 mg. of formaldehyde. 
(C) Hydrogen -peroxid. — An approximately 3% solution. If the hydrogen per- 
oxid solution is acid, neutralize with (b), using litmus solution as indicator. 

(d) Litmus solution. — A solution of purified litmus. 

65 DETERMINATION. 

Measure 50 cc. of N/l sodium hydroxid into a 500 cc. Erlenmeyer flask and add 
50 cc. of the hydrogen peroxid. Then add 3 grams of the formaldehyde solution un- 
der examination, allowing the point of the pipette to reach nearly to the liquid in the 
flask. Place a funnel in the neck of the flask and heat on the steam bath for 5 min- 
utes, shaking occasionally. Remove from the steam bath, wash the funnel with 
water, cool the flask to about room temperature, and titrate with N/l acid, using 
the litmus solution as indicator. It is necessary to cool the flask before titration 
with the acid to get a sharp end point with the litmus. Calculate the per cent of 
formaldehyde. 

Cyanid Method.^° — Official. 

66 REAGENTS. 

(a) N/10 silver nitrate. 

(b) N/10 ammonium sulphocyanate. 

(C) Potassium cyanid solution. — Dissolve 3.1 grams of potassium cyanid in 500 
cc. of water. 

(d) 50% nitric acid. 

67 DETERMINATION. 

Treat 15 cc. of the N/10 silver nitrate with 6 drops of the 50% nitric acid in a 
50 cc. volumetric flask; add 10 cc. of the potassium cyanid solution, dilute to the 
mark, shake well, filter through a dry filter and titrate 25 cc. of the filtrate with 
N/10 ammonium sulphocyanate as directed under III, 1 5. Acidify another 15 cc. 
portion of the N/10 silver nitrate with 6 drops of the 50% nitric acid and treat with 
10 cc. of the potassium cyanid solution to which has been added a measured quan- 
tity (the weight of which must be calculated from the specific gravity) of the for- 
maldehyde solution containing not over 2.5 grams of a 1% solution or the equiva- 
lent. Make up to 50 cc, filter and titrate a 25 cc. aliquot with the N/10 ammonium 
sulphocyanate for the excess of silver as before. The difference between the num- 
ber of cc. of N/10 ammonium sulphocyanate used in these 2 titrations, multiplied 



76 METHODS OF ANALYSIS [Chap. 

by 2, gives the number of cc. of N/10 ammonium sulphocyanate corresponding to 
the potassium cyanic! used by the formaldehyde. Calculate the per cent of for- 
maldehyde present i^l cc. of N/10 ammonium sulphocyanate is equivalent to 3 mg. of 
formaldehyde (HCHO)). 

LIME-SULPHUR SOLUTIONS. ^^ 

TOTAL SULPHUR.— OFFICIAL. 

68 PREPARATION OF SOLUTION. 

Weigh 10 grams of the solution and dilute to the mark in a 250 cc. graduated 
flask with recently boiled and cooled water. 

69 DETERMINATION. 

Transfer a 10 cc. aliquot to a 400 cc. beaker, add about 3 grams of sodium peroxid, 
cover immediately with a watch glass and warm on the steam bath, with frequent 
shaking, until all the sulphur is oxidized to sulphate, adding more sodium peroxid 
if necessary. Dilute, acidify with hydrochloric acid, evaporate to dryness, treat 
with water acidified with hydrochloric acid, boil, and filter to remove silica, if pres- 
ent. Dilute the filtrate to 300 cc, add 50 cc. of concentrated hydrochloric acid," 
heat to boiling, and precipitate with 10% barium chlorid solution slowly and stir- 
ring constantly. (The rate is best regulated by attaching a suitable capillary tip 
to the burette containing the barium chlorid solution.) Evaporate to dryness on 
the steam bath, take up with hot water, filter through a quantitative filter paper, 
wash until free from chlorin, ignite and heat to constant weight over a Bunsen 
burner. Calculate the sulphur from the weight of barium sulphate. Previous to 
use test the reagents for sulphur and, if present, make corrections accordingly. 

SULPHID SULPHUR.— OFFICIAL. 

70 REAGENT. 

Ammoniacal zinc solution. — Dissolve 50 grams of pure zinc chlorid in water, add 
ammonium hydroxid in sufficient quantity to redissolve the precipitate first formed, 
then add 50 grams of ammonium chlorid^' and dilute to 1 liter. 

71 DETERMINATION. 

Dilute 10 cc. of the solution, prepared as directed under 68, to about 100 cc. and 
add the ammoniacal zinc solution until the sulphid is all precipitated, indicated by 
the addition of a drop of the clear solution to a few drops of nickel sulphate solution. 
Filter immediately, wash the precipitate thoroughly with cold water and transfer 
it and the filter paper to a beaker. Cover with water, disintegrate with a glass rod 
and add about 3 grams of sodium peroxid, keeping the beaker well covered with a 
watch glass. Warm on the steam bath with frequent shaking until all the sulphur 
is oxidized to sulphate, adding more sodium peroxid if necessary. Make slightly 
acid with hydrochloric acid, filter to remove shreds of filter paper, wash thoroughly 
with hot water, and determine the sulphur in the filtrate exactly as under 69. 

72 THIOSULPHATE SULPHUR.— OFFICIAL. 

Dilute 50 cc. of the solution, prepared as under 68, to about 100 cc. in a 200 cc. 
graduated flask. Add a slight excess of the ammoniacal zinc chlorid and dilute to 
the mark. Shake thoroughly and filter through a dry filter. To 100 cc. of the fil- 
trate add a few drops of methyl orange and exactly neutralize with N/10 hydrochloric 



Vn] INSECTICIDES AND FUNGICIDES 77 

acid. Titrate this neutral solution with approximately N/20 iodin, 3 (C), using a 
few drops of starch solution as indicator. From the number of cc. of iodin solu- 
tion used, calculate the thiosulphate sulphur present. 

73 SULPHATE SULPHUR.— OFFICIAL. 

To the solution from the determination in 72, add 2 or 3 drops of hydrochloric 
acid, precipitate in the cold with 10% barium chlorid solution, allow to stand over- 
night, filter, calculate the sulphur from the weight of barium sulphate and report 
as sulphate sulphur. 

74 TOTAL LIME.— OFFICIAL. 

To 25 cc. of the solution, prepared as under 68, add 10 cc. of concentrated hydro- 
chloric acid, evaporate to dryness on the steam bath, treat with water and a little 
hydrochloric acid, warm until all the calcium chlorid is dissolved, and filter from sul- 
phur and any silica that may be present. Oxidize the filtrate by boiling with a 
little concentrated nitric acid, make ammoniacal, filter from iron and aluminium 
if present, heat to boiling and precipitate the calcium with ammonium oxalate so- 
lution. Filter, wash and ignite over a blast lamp to constant weight; weigh the 
residue as calcium oxid. 

BIBLIOGRAPHY. 

1 J. Ind. Eng. Chem., 1916, 8: 327. 

2 Ibid., 1909, 1: 208. 

' J. Assoc. Official Agr. Chemists, 1915, 1: 436, 446. 

* J. Am. Chem. Soc, 1901, 23: 115. 

« Ibid., 1902, 24: 1082. 

e Ibid., 1900, 22: 802. 

-> U. S. Bur. Chem. Bull. 122, p. 106. 

8 Am. J. Sci., 1890, 3rd ser., 40: 66. 

' U. S. Bur. Chem. Bull. 137, p. 40. 
'0 Ibid., 105, p. 166. 
" Ibid., p. 167. 

12 Fresenius. Quantitative Chemical Analvsis. Revised and amplified transla- 
tion of the 6th German ed., 2: 1180; U. S. Geol. Surv. Bull. 422, p. 179. 
'3 Sutton. Volumetric Analysis. 10th ed., 1911, p. 207. 
1^ Ibid., 9th ed., rev., p. 201. 

1^ Lewkowitsch. Chemical Technology and Analysisof Oils, Fats and Waxes. 5th 
ed., 1915, 3: 348. 
'« Ibid., 346. 
" Sutton. Volumetric Analysis. 10th ed., 1911, p. 61. 

18 U. S. Bur. Animal Industry, Bull. 133. 

19 Ber., 1898, 31: 2979; J. Am. Chem. Soc, 1905, 27: 1183; U. S. Bur. Chem. Bull. 
99, p. 30; 132, p. 49; 137, p. 47. 

20 Z. anal. Chem., 1897, 36: 18; U.S. Bur. Chem. Bull. 132, p. 49. 

21 J. Assoc. Official Agr. Chemists, 1915, 1 : 76. 
" J. Am. Chem. Soc, 1911, 33: 844. 

" J. Soc. Chem. Ind., 1912, 31: 369. 



VIII. FOODS AND FEEDING STUFFS. 

1 PREPARATION OF SAMPLE.— OFFICIAL. 

Grind the sample so that it will pass through a sieve having circular openings 
-^ inch (1 mm.) in diameter. If the sample can not be ground, reduce it to as fine a 
state as possible. 

MOISTURE. 

2 Direct Drying. — Official. 

Dry a quantity of the substance, representing about 2 grams of dry material, 
in a current of dry hydrogen or in vacuo at the temperature of boiling water to 
constant weight (approximately 5 hours). If the substance be held in a glass vessel, 
the latter should not be in contact with the boiling water. 

3 Drying in Vacuo without Heat. — Tentative. 

Mix the sample thoroughly and weigh by difference 2-5 gram portions from a 
stoppered weighing bottle into tared, covered crucibles. Where subsequent fat 
determinations are to be made, fat extraction cones may be used. Substances that 
dry down to horn-like material should be mixed with fat-free cotton or other suit- 
able material (previously tared with the container). Place 200 cc. of fresh concen- 
trated sulphuric acid in a strong, tight 6 inch vacuum desiccator. Put triplicate 
samples in separate desiccators, and exhaust by means of a vacuum pump. If a 
pump is not available, place 10 cc. of ether in a small beaker in the desiccator, and 
exhaust with a water filter pump. 

Between the pump and the desiccator interpose an empty bottle, next to the 
desiccator, and a bottle of water. Draw the air from the desiccator through the 
water and turn the desiccator stop-cock at just the instant when the water begins 
to rise in the tube leading from the empty bottle. 

Gently rotate the desiccator 4 or 5 times during the first 12 hours to mix the sul- 
phuric acid with the water which has collected as an upper layer. At the end of 24 
hours open the desiccator, forcing the incoming air to bubble through concentrated 
sulphuric acid, and make the first weighing. After weighing place in a desiccator 
containing fresh concentrated sulphuric acid and exhaust as before. Rotate the 
desiccator several times during the interval and weigh again after a suitable period 
of drying. Repeat this process of drying in vacuo over sulphuric acid until the 
weight is constant. 

4 ASH.— OFFICIAL. 

Char a quantity of the substance, representing about 2 grams of the dry material, 
and burn until free from carbon at a low heat, not to exceed dull redness. If a 
carbon-free ash can not be obtained in this manner, exhaust the charred mass with 
hot water, collect the insoluble residue on a filter, burn till the ash is white or nearly 
so, and then add the filtrate to the ash and evaporate to dryness. Heat to low 
redness till the ash is white or grayish white and weigh. 

79 



80 METHODS OF ANALYSIS [Chap. 

5 CRUDE PROTEIN.— OFFICIAL. 

Determine nitrogen as directed under 1, 18, 21 , or 23, and multiply the result by 
6.25. 

ALBUMINOID NITROGEN.— OFFICIAL. 

6 UEAGENT. 

SUitzcr's reagent. — Prepare cupric hydroxid as follows: Dissolve 100 grams of pure 
copper sulphate in 5 liters of water, add 2.5 cc. of glycerol, and then dilute sodium 
hydroxid solution until the liquid is just alkaline; filter, rub the precipitate up with 
water containing 5 cc. of glycerol per liter, and wash by decantation or filtration 
until the washings are no longer alkaline. Rub the precipitate up again in a mortar 
with water containing 10% of glycerol, thus preparing a uniform gelatinous mass 
that can be measured with a pipette. Determine the quantity of copper hydroxid 
per cc. of this mixture. 

7 DETERMINATION. 

Place 0.7 gram of the substance in a beaker, add 100 cc. of water, and heat to 
boiling; or, in case of substances rich in starch, heat on the water bath for 10 minutes; 
add a quantity of the Stutzer's reagent containing about 0.5 gram of the hydroxid; 
stir thoroughly, filter when cold, wash with cold water, and, without removing the 
precipitate from the filter, determine the nitrogen according to I, 18, 21 or 23, 
adding sufficient potassium sulphid solution to completely precipitate all of the 
copper and mercury. The filter paper used must be practically free from nitrogen. 
If the material (such as seeds, seed residue, or oil cake) is rich in alkaline phos- 
phates, add, to decompose the alkaline phosphates, 1-2 cc. of a concentrated potash 
or soda alum solution, free from ammonia, then the copper hydroxid, and mix well 
by stirring. If this is not done, copper phosphate and free alkali may be formed, 
and the protein-copper precipitate partially dissolved in the alkaline liquid. 

8 AMIDO NITROGEN.— OFFICIAL. 

Subtract the amount of albuminoid nitrogen from the amount of total nitrogen 
to obtain the amido nitrogen. 

CRUDE FAT OR ETHER EXTRACT. 

Direct Method. — Official. 

9 REAGENT. 

Anhydrous ether. — Wash any of the commercial brands of ether with 2 or 3 suc- 
cessive portions of water, add solid sodium or potassium hydroxid, and let stand 
until most of the water has been abstracted from the ether. Decant into a dry 
bottle, add small pieces of carefully cleaned metallic sodium, and let stand until 
there is no further evolution of hydrogen gas. Keep the ether, thus dehydrated, 
over metallic sodium in lightly stoppered bottles. 

1 DETERMINATION. 

Large quantities of soluble carbohydrates may interfere with the complete ex- 
traction of the fat. In such cases extract with water before proceeding with the 
determination. Extract about 2 grams of material, dried as under 2 or 3, with the 
anhydrous ether for 16 hours. Dry the extract at the temperature of boiling water 
for 30 minutes, cool in a desiccator, and weigh; continue, at 30 minutes intervals, 
this alternate drying and weighing to constant weight. For most feeds a period 
of 1-1 J hours is required. 



Vni] FOODS AND FEEDING STUFFS 81 

11 Indirect Method.— Ojficial. 

Determine the moisture, as directed in 2 or 3, then extract the dried substance 
for 16 hours as directed under 10, dry again and regard the loss of weight as ether 
extract. 

Sucrose. 

OPTICAL METHODS. 

12 GENERAL DIRECTIONS FOR RAW SUGARS.— TENTATIVE. 

(Rules' of the International Commission for Unifying Methods of Sugar An.alysis.) 

"In general all polarizations are to be made at "JO'-^C." 

"The verification of the saccharimeter must also be made at 20°C. For instru- 
ments using the Ventzke scale 26 grams of pure dry sucrose, weighed in air with 
brass weights, dissolved in 100 metric cc. at 20^0. and polarized in a room, tlie tem- 
perature of which is also 20''C., must give a saccharimeter reading of exactly 100.00. 
The temperature of the sugar solution during polarization must be kept constant 
at 20'C." 

"For countries where the mean temperature is higher than 20''C., saccharimeters 
may be adjusted at SO^C. or any other suitable temperature, under the conditions 
specified above, provided that the sugar solution be made up to volume and polarized 
at this same temperature." 

"In etTecting the polarization of substances containing sugar employ only half- 
shade instruments." The saccharimeter used can be either single or double wedge 
and should be a half-shadow instrument with either double or triple field. 

"During the observation keep the apparatus in a fixed position and so far removed 
from the source of light that the polarizing Nicol is not warmed." 

"As sources of light employ lamps which give a strong illumination such as 
triple gas burner with metallic cylinder, lens and reflector; gas lamps with Auer 
(Welsbach) burner; electric lamp; petroleum duplex lamp; sodium light." When- 
ever there is any irregularity in the sources of light such as that due to tlie convolu- 
tions of the filament in the case of electric light or to the meshes of the gauze in the 
case of the Welsbach light, place a thin ground-glass plate between the source of 
light and the polariscope so as to render the illumination uniform. 

"Before and after each set of observations the chemist must satisfy himself of the 
correct adjustment of his saccharimeter by means of standardized quartz plates. 
He must also previously satisfy himself of the accuracy of his weights, polarization 
flasks, observation tubes and cover-glasses. (Scratched cover-glasses must not be 
used.) Make several readings and take the mean thereof, but no one reading may 
be neglected." Such plates are standardized to read to the second decimal point 
and by their use a quick ancl at the same time accurate test can be made. In using 
such plates for testing saccharimeters, it is necessary that the instrument, as well as the 
plate, be at 20°C. before making a reading. Different points of the scale, preferably 
20°, 50°. S0°, and 100°, (sugar scale) should be tested against the plates. 

"In making a polarization use the whole normal weight for 100 cc. or a multiple 
thereof for any corresponding volume." 

"As clarifying and decolorizing agents use either basic acetate of lead, alumina 
cream, or concentrated solution of alum. Boneblack and decolorizing powders are 
to be excluded." Whenever reducing sugars are determined in the solution for po- 
larizing, use only neutral lead acetate for clarification as basic lead acetate causes 
precipitation of some of the reducing sugars. In addition to these clarifying agents, 



82 METHODS OF ANALYSIS [Chap. 

neut ral lead acetate and basic lead nitrate (Herles' solution) have been made official 
by tlio AHHociaiion. 

"After bririKiriK the solution oxactly to tho mark at the proper tcmporaturc, and 
after wiping out the neck of the flask with filter paper, pour all of the well-shaken 
clarified sugar solution on a rapidly acting filter. Reject the first portions of the 
filtrate, and use the rest, which must be perfectly clear, for polarization." It is 
aflvinjiblo to reject the first 20 cc. that run through, then cover the funnel with a 
watch glass and use tho remainder for polarization. In no case should the whole 
solution or any part be rciturncd to tho filter. If cloudy after the 20 cc. have been 
rejected, Ijogin a now childrmiiiation. 

"Wlwuiovor white light is used in pol!i,ritn(;tric determinations, the same must be 
filtered tlirough a solution of polnssiuin diclirorriiite of such a concentration that the 
percentage content of tin; solution multiplied by the length of the column of the solu- 
tion in centimeters is equal to nine." This concentration must be doubled in 
reading carbohydrate materials of high rotation dispersion, such as commercial 
glucose, «tc. 

13 PREPARATION AND USE OF CLARIFYING REAGENTS.— TENTATIVE. 

(a) Basic lead acetate solution. — Boil 430 grams of neutral lead acetate, 130 grams 
of litharge, ntid 1 liter of water for 30 minutes. Allow the mixture to cool and settle 
and (lilul.o tli(! Hupornataiit litpiid to a specific gravity of 1.25 with recently boiled 
wat(T. Solid basic h-ad acetate may be substituted for the normal salt and litharge 
in th(! pr('|);vral,i()n of the solution. 

(b) Alumina cream.. — Prepare a cold saturatcMJ solution of alum in water. Add 
airunonium hydroxid with constant stirring until the solution is alkaline to litmus, 
allow the precipitate to settle and wash by decantation with water until the wash 
water gives only a slight test for sulphates with barium chlorid solution. Pour ofT 
the excess of water and store the residual cream in a stoppered bottle. 

(C) Dry basic lead acetate {Ilorne method). — This clarifying agent is obtained as 
a dry powdtrnul Halt and should contain 72.8% of lead, which corresponds to a com- 
position of ;{Pb(C^2ll3<^)2)22Pb(). Dissolve the normal or half-normal weight of the 
sugar solution in a flask with waler and complete the volume. Add a small quantity 
of the dry salt and shako, then add more and shako again, repeating until completely 
preci|)it,atod but avoiding any excess. Of this salt 0.1340 gram is equivalent to 1 cc. 
of the basic lead acetate solution, described under (a). When molasses or any other 
substance producing a heavy precipitate is being clarified, some dry, coarse sand 
should be added to l)reak up the balls of basic lead acetate and the precipitate. 
(This method is to have oqmil weight with the use of a solution of basic lead acetate 
in clarifying cano, sorghum, and boot products.) 

(d) Neutral lend acetate. — Prepare a saturated solution of ncMitral load acetate and 
add it to the sugar solution before completing to volume. Its use is imperative when 
deterruining the reducing sugars in tho solution used for polarization. 

(e) lUiKic lead nitrate {Ilerleti' .s•o^»7/u>n).—(l) Dissolve 250 grams of lead nitrate 
in water and make up to 500 cc. (2) Dissolve 25 grams of sodium hydroxid in water 
and make up to 500 cc. 

Add equal amounts of (1) and (2) to the sugar solution, shake, and add more if 
complete precipitation has not occurred, but avoid any excess. Then complete 
the volume with waler. When this solution is used for clarification, the factor in the 
Clergot determination becomes 113.5 instead of 142. GO. 



Vni] FOODS AND FI5EDING STUFFS 83 

DETERMINATION OF SUCROSE IN THE ABSENCE OF RAFFINOSE. 

(In the presence of much levulose, as in honeys and fruits products, the optical 
method for sucrose gives too high a result.) 

14 By Polarization Before and After Inversion with Hydrochloric Acid. — Official. 

Dissolve the normal weight (26 grams) of the substance in water, add basic lead 
acetate carefully, avoiding any excess, then 1-2 cc. of alumina cream, shake, and 
dilute to 100 metric cc, filter, rejecting the first 20 cc. of the filtrate, cover the 
filter with a watch glass and, when sufficient filtrate is collected, polarize in a 200 
mm. tube. The reading so obtained is the direct reading (I' of formula given be- 
low) or polarization before inversion. For the invert reading, remove the lead from 
the solution cither (1) by adding anhydrous potassium oxalate, a little at a time, 
to the remaining solution, avoiding an excess and removing the precipitated lead 
by filtration; or, (2) by adding anhydrous sodium carbonate under the same con- 
ditions. Introduce 50 cc. of the lead-free filtrate into a 100 cc. fiask (if sodium 
carbonate was used for removing the lead, neutralize carefully the excess of sodium 
carbonate with a few drops of dilute hydrochloric acid) and add 25 cc. of water. 
Then add, little by little, while rotating the flask, 5 cc. of hydrochloric acid, (sp.gr. 
1.20). Heat the flask after mixing, in a water bath kept at 70°C. The temperature 
of the solution in the flask should reach <>7°-()d''C in 2.J-3 minutes. Maintain a 
temperature of as nearly WC as possible for T-?^ minutes, making the total time 
of heating 10 minutes. Remove the flask and cool the contents rapidly to 20°C. 
and dilute to 100 cc. Polarize this solution in a tube provided with a lateral branch 
and a water jacket, maintaining a temperature of 20°C. This reading must be 
multiplied by 2 to obtain the invert reading. If it is necessary to work at a tem- 
perature other than 20^0., which is allowable within narrow limits, the volumes 
must be completed and both direct and invert polarizations must be made at exactly 
the same temperature. 

The inversion may also be accomplished as follows: (1) To .50 cc. of the clarified 
solution, freed from lead, add 5 cc. of hydrochloric acid (sp. gr. 1.20) and set aside 
for 24 hours at a temperature not below 20^0. ; or ,(2) If the temperature be above 
25°C. set aside for 10 hours. Make up to 100 cc. at 20°C. and polarize as directed 
above. 

Calculate sucrose by one of the following formulas: 

For substances in vjhich the invert solution contains more than 12 grarns of invert 
sugar per WO cc. — The following formula is to be used when substances like raw 
sugars are polarized: 

^, 100 (P - I) . ... 
,S = ^^ in which 

142.66 

2 

S = per cent of sucrose; 

P = direct reading normal solution; 

I = invert reading normal solution; 

T = temperature at which readings are made. 
For substances in which the concentration of the invert solution is less than 12 grama 
per 100 cc. — The following formula, which takes into account the concentration of the 
sugar in solution, should be used in all other cases. 



84 METHODS OF ANALYSIS [Chap. 

100 (P - I) 



142.66- ^ - 0.0065 ri42.66 - | - (P - 1)1 



in which 



S = per cent of sucrose; 
P = direct reading normal solution; 
I = invert reading normal solution; 
T = temperature. 

By Polarization Before and After Inversion with Invertase. — Tentative. 

15 REAGENT. 

Invertase solution (Hudson Method.^) — Mix 1 kilo of pressed baker's or brewer's 
yeast with 1 liter of tap water and 50 cc. of toluene and keep at room temperature 
2-3 days to allow autolysis to proceed to the stage of maximum inverting activity. 
Then add neutral lead acetate in slight excess, filter, precipitate the lead in the 
filtrate with hydrogen sulphid, filter again and then dialyze the filtrate thoroughly 
in a collodion sac. Preserve in an ice box the dialyzed solution with the addition 
of a little toluene to prevent the growth of micro-organisms. Note the optical 
activity of the invertase solution and correct the invert reading according to the 
amount of the solution used. 

1 6 DETERMINATION. 

Dissolve the normal weight (26 grams) of the substance in water, clarify, make 
up to volume, and take the direct polarization (P) as directed under 14. If lead 
has been used as a clarifying agent, remove the excess of lead from the filtrate, with 
anhydrous sodium carbonate or potassium oxalate, and filter. To 50 cc. of the 
filtrate in a 100 cc. flask add acetic acid, drop by drop, until the reaction is acid to 
litmus, add 10 cc. of the invertase solution, fill the flask with water nearly to 100 cc. 
and let stand in a warm place (about 40°C.) overnight. Cool and make up to 100 cc. 
at 20°C. Polarize at 20°C. in a 200 mm. tube. Allow the solution to remain in the 
tube for an hour and repeat the polarization. If there is no change from the pre- 
vious reading, the inversion is complete, whereupon the reading and temperature 
of the solution are carefully noted. Correct the reading for the optical activity 
of the invertase solution and then multiply by 2. Calculate the percentage of 
sucrose by the following formula: 

„ 100 (P - I) ■ I- u 

S = lu which 

T FT ~\ 

142 - - - 0.0065 I 142 - - - (P - I) J 

S = per cent of sucrose; 

P = direct reading; 

I = invert reading; 

T = temperature at which invert reading is made. 

1 7 DETERMINATION OF SUCROSE AND RAFFINOSE.— OFFICIAL. 

(Of value chiefly in the analysis of beet products.) 

If the direct reading is more than 1° higher than the per cent of sucrose as • al- 
culated by the formula given under 14, raffinose is probably present. Calculate 
sucrose and raffinose by the following formula of Herzfeld: 



VIII] FOODS AND FEEDING STUFFS 85 

„ 0.5124 P - I ^ P - S . 

S = 'z~;:^rz ) R = in which 

0.839 1.852 

P = direct reading normal solution; 
I = invert reading normal solution; 
S = per cent of sucrose; 
R = per cent of anhydrous rafEnose. 

The above formula assumes that the polarizations are made at exactly 20°C. 
If the temperature (T) is other than 20°C., the following formula should be used: 

P (0.4724 + 0.002 T) -I 
0.899 - 0.003 T 

P- S 



Having calculated S, then R = 



1.852 



CHEMICAL METHODS. 

1 8 DETERMINATION OF SUCROSE FROM REDUCING SUGARS BEFORE AND AFTER 

INVERSION.— TENTATIV E. 

Determine the reducing sugars (clarification having been effected with neutral 
lead acetate, never with basic lead acetate), as directed under 25, and calculate to 
invert sugar from 27. Invert the solution as directed under 14 or 16, exactly 
neutralize the acid, and again determine the reducing sugars, but calculate them 
to invert sugar from the same table as referred to above, using the invert sugar 
column alone. Deduct the percentage of invert sugar obtained before inversion 
from that obtained after inversion, and multiply the difference by 0.95, the result 
being the per cent of sucrose. The solutions should be diluted in both determina- 
tions so that not more than 245 mg. of invert sugar are present in the amount 
taken for reduction. It is important that all lead be removed from the solution 
with potassium oxalate before reduction. 

Reducing Sugars. 

invert sugar. 

Approximate Volumetric Method for Rapid Work. — Tentative. 

19 REAGENT. 

Soxhlet's Modification of Fehling's Solution. — Prepare by mixing, immediately 
before use, equal volumes of (a) and (b). 

(a) Copper .sulphate solution. — Dissolve 34.639 grams of copper sulphate (CUSO4 
5H2O) in water, dilute to 500 cc. and filter through prepared asbestos. 

(b) Alkaline tartrate solution. — Dissolve 173 grams of Rochelle salts and 50 grams 
of sodium hydroxid in water, dilute to 500 cc, allow to stand for 2 days and filter 
through prepared asbestos. 

20 STANDARDIZATION OF COPPER SOLUTION. 

Since the factor of calculation varies with the minute details of manipulation, 
every operator must determine a factor for himself, using a known solution of the 
pure sugar that he desires to determine, and keeping the conditions the same as 
those used for the determination. 



86 METHODS OF ANALYSIS [Chap. 

Stiindardize the solution for invert sugar in the following manner: 
Dissolve 4.75 grams of pure sucrose in 75 cc. of water, add 5 cc. of hydrochloric 
acid (sp. gr. 1.20) and invert as directed under 14. Neutralize the acid with sodium 
hydroxid solution and dilute to 1 liter. Ten cc. of this solution contain 0.050 gram of 
invert sugar, which should reduce 10 cc. of the reagent. The strength of the copper 
solution should never be taken as a constant, but should be checked against the 
sugar. 



21 



DETERMINATION. 



Place 10 CC. of the reagent in a large test tube and add 10 cc. of water. Heat to 
boiling, and add gradually small portions of the solution of the material to be tested 
until the copper has been completely reduced, boiling after each addition to com- 
plete the reaction. Two minutes' boiling is required for complete reduction when 
the full amount of sugar solution has been added in one portion. When the end 
is nearly reached and the amount of sugar solution to be added can no longer be 
judged by the color of the solution, remove a small portion of the liquid and filter 
rapidly into a small porcelain crucible or on a test plate; acidify with dilute acetic 
acid, and test for copper with dilute potassium ferrocyanid solution. The sugar 
solution should be of such strength as will give a burette reading of 15-20 cc, and 
the number of successive additions should be as small as possible. 

Soxhlet Volumetric Method. — Tentative, 

22 REAGENT. 

The reagent used is described under 19. 



23 



DETERMINATION. 



Make a preliminary titration to determine the approximate percentage of reduc- 
ing sugar in the material under examination. Prepare a solution which contains 
approximately 1% of reducing sugar. Place in a beaker 100 cc. of the reagent and 
approximately the amount of the sugar solution for its complete reduction. Boil 
for 2 minutes. Filter through a folded filter and test a portion of the filtrate for 
copper by use of dilute acetic acid and dilute potassium ferrocyanid solution. Re- 
peat, varying the volume of sugar solution, until 2 successive amounts are found 
which differ by 0.1 cc, one giving complete reduction and the other leaving a small 
amount of copper in solution. The mean of these 2 readings is taken as the volume 
of the solution required for the complete precipitation of 100 cc. of the reagent. 

Under these conditions 100 cc. of the reagent require 0.494 gram of invert sugar 
for complete reduction. Calculate the percentage by the following formula: 

V = the volume of the sugar solution required for the complete reduction of 

100 cc. of the reagent; 

W = the weight of the sample in 1 cc. of the sugar solution; 

100 X 0.494 , . . 

:^^ = per cent of invert sugar. 

GRAVIMETRIC METHODS. 
Munson and Walker General Method.^ — Tentative. 

24 REAGENTS. 

(a) Asbestos. — Digest the asbestos, which should be the amphibole variety, with 
dilute hydrochloric acid (1 to 3) for 2-3 days. Wash free from acid, digest for a 



VIII] FOODS AND FEEDING STUFFS 87 

similar period with 10% sodium hydroxid solution, and then treat for a few hours 
with hot alkaline tartrate solution (old alkaline tartrate solutions that have stood 
for some time may be used for this purpose) of the strength employed in sugar de- 
terminations. Then wash the asbestos free from alkali, digest for several hours 
with dilute nitric acid (1 to 3) and, after washing free from acid, shake with water 
into a fine pulp. In preparing the Gooch crucible, make a film of asbestos ? inch 
thick and wash thoroughly with water to remove fine particles of asbestos. If the 
precipitated cuprous oxid is to be weighed as such, wash the crucible with 10 cc. of 
alcohol, then with 10 cc. of ether, dry for 30 minutes at 100°C., cool in a desiccator 
and weigh. 

(b) The solution used is described under 19. 

25 PRECIPITATION OF CUPROUS OXID. 

Transfer 25 cc. each of the copper sulphate and alkaline tartrate solutions to a 
400 cc. beaker of alkali-resisting glass and add 50 cc. of reducing sugar solution, or, 
if a smaller volume of sugar solution is used, add water to make the final volume 
100 cc. Heat the beaker upon an asbestos gauze over a Bunsen burner, regulate the 
flame so that boiling begins in 4 minutes, and continue the boiling for exactly 2 
minutes. (It is important that these directions be strictly observed and, in order 
to regulate the burner for this purpose, it is advisable to make preliminary tests, 
using 50 cc. of the reagent and 50 cc. of water before proceeding with the actual 
determination.) Keep the beaker covered with a watch glass during the heating. 
Filter the cuprous oxid at once on an asbestos mat in a porcelain Gooch crucible, 
using suction. Wash the cuprous oxid thoroughly with water at a temperature of 
about 60°C., and either weigh directly as cuprous oxid as in 26, or, determine the 
amount of reduced copper by one of the methods under 29-34, respectively. Con- 
duct a blank determination, using 50 cc. of the reagent and 50 cc. of water, and, if 
the weight of cuprous oxid obtained exceeds 0.5 mg., correct the result of the reducing 
sugar determination accordingly. The alkaline tartrate solution deteriorates on 
standing and the amount of cuprous oxid obtained in the blank increases. 

Determination of Reduced Copper. 

26 I. Direct Weighing of Cuprous Oxid. — Tentative. 

Prepare a Gooch as directed under 24 (a). 

Collect the precipitated cuprous oxid on the mat, as directed under 25, wash 
thoroughly with hot water, then with 10 cc. of alcohol, and finally with 10 cc. of 
ether. Dry the precipitate for 30 minutes in a water oven at the temperature of 
boiling water; cool and weigh. Calculate the weight of metallic copper. Obtain 
from 27 the weight of invert sugar equivalent to the weight of copper found. 

This method should be used only for determinations in pure sugar solutions. In 
all other products the copper of the cuprous oxid should be determined by one of the 
following methods, since the cuprous oxid is very apt to be contaminated with 
foreign matter. 

The number of milligrams of copper reduced by a given amount of reducing sugar 
differs when sucrose is present and when it is absent. In the tables the absence of 
sucrose is assumed except in the two columns under invert sugar, where one for 
mixtures of invert sugar and sucrose containing 0.4 gram of total sugar in 50 cc. of 
solution, and one for invert sugar and sucrose when the 50 cc. of solution contains 2 
grams of total sugar are given, in addition to the column for invert sugar alone. 



METHODS OF ANALYSIS 



[Chap. 



27 



Table 1. — Munson and Walker's Table. 



For calculating dextrose, invert sugar alone, invert sugar in the presence of sucrose 
(0. 4 gram and 2 grams total sugar), lactose {Iwo forms), and maltose {anhydrous and 
crystallized). 

[Expressed in milligrams.] 







^.^ 






1 




1 




1 




— 


3 


9 

o 

■« 

a 

o 
o 


at 

o 
o 
p 

o 

(9 

O 
03 

H 

a 

Q 


o 
p 

01 

H 

a 
> 


INVERT SUGAR 
AND 8DCBOSE 


LACTOSE 


MALTOSE 


3 

o 

o 

o 
m 

P 
o 
PS 
B. 
P 
V 




o 



o 

CO 

U 

o 

* 

p 
t> 


3 

o 

3 
o 


3 

o 

603 


6 

w 

6 


O 

q 
6 


5 
6 


O 

o 
d 




10 


8.9 


4.0 


4.5 


1.6 




3.8 


4.0 


5.9 


6.2 


10 




11 


9.8 


4.5 


5.0 


2.1 




4.5 


4.7 


6,7 


7.0 


11 




12 


10.7 


4.9 


5.4 


2.5 




5.1 


5.4 


7.5 


7.9 


12 




13 


11.5 


5.3 


5.8 


3.0 




5.8 


6.1 


8.3 


8.7 


13 




14 


12.4 


5.7 


6.3 


3.4 




6.4 


6.8 


9.1 


9.5 


14 




15 


13.3 


6.2 


6.7 


3.9 




7.1 


7.5 


9.9 


10.4 


15 




16 


14.2 


6.6 


7.2 


4.3 




7.8 


8.2 


10.6 


11.2 


16 




17 


15.1 


7.0 


7.6 


4.8 




8.4 


8.9 


11.4 


12.0 


17 




13 


16.0 


7.5 


8.1 


5.2 




9.1 


9.5 


12.2 


12.9 


18 




19 


16.9 


7.9 


8.5 


5.7 




9.7 


10.2 


13.0 


13.7 


19 




20 


17.8 


8.3 


8.9 


6.1 




10.4 


10,9 


13.8 


14.6 


20 




21 


18.7 


8.7 


9.4 


6.6 




11.0 


11.6 


14.6 


15.4 


21 




22 


19.5 


9.2 


9.8 


7.0 




11.7 


12.3 


15,4 


16.2 


22 




23 


20.4 


9.6 


10.3 


7.5 




12.3 


13.0 


16.2 


17.1 


23 




24 


21.3 


10.0 


10.7 


7.9 




13.0 


13.7 


17.0 


17.9 


24 




25 


22.2 


10.5 


11.2 


8.4 




13.7 


14.4 


17.8 


18.7 


25 




26 


23.1 


10.9 


11.6 


8.8 




14.3 


15.1 


18.6 


19.6 


26 




27 


24.0 


11.3 


12.0 


9.3 




15.0 


15.8 


19.4 


20.4 


27 




28 


24.9 


11 8 


12,5 


9.7 




15.6 


16.5 


20.2 


21.2 


28 




29 


25.8 


12.2 


12.9 


10.2 




16.3 


17.1 


21.0 


22.1 


29 




30 


26.6 


12.6 


13.4 


10.7 


4.3 


16.9 


17.8 


21.8 


22.9 


30 




31 


27.5 


13.1 


13.8 


11.1 


4.7 


17.6 


18.5 


22.6 


23.7 


31 




32 


28.4 


13.5 


14.3 


11.6 


5.2 


18,3 


19.2 


23,3 


24.6 


32 




33 


29.3 


13.9 


14.7 


12.0 


5.6 


18.9 


19.9 


24,1 


25.4 


33 




34 


30.2 


14.3 


15.2 


12.5 


6.1 


19.6 


20.6 


24.9 


26.2 


34 




35 


31.1 


14.8 


15.6 


12.9 


6.5 


20.2 


21.3 


25.7 


27.1 


35 




3S 


32.0 


15.2 


16.1 


13.4 


7.0 


20,9 


22.0 


26.5 


27.9 


36 




37 


32.9 


15.6 


16.5 


13.8 


7.4 


21.5 


22.7 


27.3 


28.7 


37 




38 


33.8 


18.1 


16.9 


14.3 


7.9 


22.2 


23.4 


28.1 


29.6 


38 




39 


34.6 


16.5 


17.4 


14.7 


8.4 


22.8 


24.1 


28.9 


30.4 


39 




40 


35.5 


16.9 


17.8 


15.2 


8.8 


23.5 


24.8 


29.7 


31.3 


40 




41 


36.4 


17.4 


18.3 


15.6 


9.3 


24.2 


25.4 


30.5 


32.1 


41 




42 


37.3 


17.8 


18.7 


16.1 


9.7 


24.8 


26.1 


31.3 


32.9 


42 




43 


38.2 


18.2 


19.2 


16.6 


10.2 


25.5 


26.8 


32.1 


33.8 


43 




44 


39.1 


18.7 


19.6 


17.0 


10.7 


20.1 


27.5 


32.9 


34.6 


44 




45 


40.0 


19.1 


20.1 


17.5 


11.1 


26.8 


28.2 


33.7 


35.4 


45 




46 


40.9 


19.6 


20.5 


17.9 


11.6 


27.4 


28.9 


34.4 


36.3 


46 




47 


41.7 


20.0 


21.0 


18.4 


12.0 


28.1 


29.6 


35.2 


37.1 


47 




48 


42.6 


20.4 


21.4 


18.8 


12.5 


28.7 


30.3 


36.0 


37.9 


48 




49 


43.5 


20.9 


21.9 


19.3 


12.9 


29.4 


31.0 


36.8 


38.8 


49 




50 


44.4 


21.3 


22.3 


19.7 


13.4 


30.1 


31.7 


37.6 


39.6 


50 




51 


45.3 


21.7 


22.8 


20.2 


13.9 


30.7 


32.4 


38.4 


40.4 


51 




52 


46.2 


22.2 


23.2 


20.7 


14.3 


31.4 


33 


39.2 


41.3 


52 




53 


47.1 


22.6 


23.7 


21.1 


14.8 


32.1 


33.7 


40.0 


42.1 


53 




54 


48.0 


23.0 


24.1 


21.6 


15.2 


32.7 


34.4 


40.8 


42.9 


54 




55 


48.9 


23.5 


24.6 


22.0 


15.7 


33.4 


35.1 


41.6 


43.8 


55 




56 


49.7 


23.9 


25.0 


22.5 


16.2 


34.0 


35.8 


42.4 


44.6 


56 




57 


50.6 


24 3 


25.5 


22.9 


16.6 


34.7 


36.5 


43.2 


45.4 


57 




58 


51.5 


24.8 


25.9 


23.4 


17.1 


35,4 


37.2 


44 


46.3 


58 




59 


52.4 


25.2 


26.4 


23.9 


17.5 


36.0 


37.9 


44.8 


47.1 


59 




60 


53.3 


25.6 


26.8 


24.3 


18.0 


36.7 


38.6 


45.6 


48.0 


60 




61 


54.2 


26.1 


27.3 


24.8 


18.5 


37.3 


39.3 


46.3 


48.8 


61 




62 


55.1 


26.5 


27.7 


25.2 


18.9 


38,0 


40,0 


47.1 


49.6 


62 




63 


56.0 


27.0 


28.2 


25.7 


19 4 


38,6 


40.7 


47.9 


50.5 


63 




64 


56.8 


27.4 


28.6 


26.2 


19.8 


39.3 


41.4 


48.7 


51.3 


64 





vin] 






FOODS 


AND 


FEEDING STUFFS 






89 


27 


Tabli 


1.— MUNSON AND WALKER'S TABLE- 


-Continued. 










[Expressed in milligrams.] 








o 




'S 




INVERT SU'AR 


LACTOSE 


MALT 


SE 


q 


3 




o 
o 

P 




AND SUCROSE 








5 


o 




__ 










o 


Q 




.J 
o 




O 






O 




o 





o 
p 


"a 
O 

K 
a 

a< 
o 
o 


m 

o 


o 



m 


a 

c3 u 


1^ 


o 


6 


o 


O 


o 




g 

D 




> 


Mm 

3 
O 


c3 <!3 
603 


6 




c5 


Si 

c5 


o 

K 


65 


57.7 


27.8 


29.1 


26.6 


20.3 


40.0 


42.1 


49.5 


52.1 


65 


66 


58.6 


28 3 


29.5 


27.1 


20.8 


40.6 


42.8 


50.3 


53.0 


66 


67 


59.5 


28.7 


30.0 


27.5 


21.2 


41.3 


43.5 


51.1 


53.8 


67 


68 


60.4 


29.2 


30.4 


28.0 


21.7 


41.9 


44.2 


51.9 


54.6 


68 


69 


61.3 


29.6 


30.9 


28.5 


22.2 


42.6 


44.8 


52.7 


55.5 


69 


70 


62.2 


30.0 


31.3 


28.9 


22.6 


43 3 


45.5 


53 5 


56.3 


70 


71 


63.1 


30.5 


31.8 


29.4 


23.1 


43.9 


46.2 


54.3 


57.1 


71 


72 


64.0 


30.9 


32.3 


29.8 


23.5 


44.6 


46.9 


55.1 


58.0 


72 


73 


64.8 


31.4 


32 7 


30.3 


24.0 


45.2 


47.6 


55.9 


58.8 


73 


74 


65.7 


31.8 


33.2 


30.8 


24.5 


45.9 


48.3 


56.7 


59.6 


74 


75 


66.6 


32.2 


33.6 


31.2 


24.9 


46.6 


49.0 


57.5 


60.5 


75 


76 


67.5 


32.7 


34 1 


31.7 


25.4 


47.2 


49.7 


58.2 


61.3 


76 


77 


68.4 


33.1 


34.5 


32.1 


25.9 


47.9 


50.4 


59.0 


62.1 


77 


78 


69.3 


33.6 


35.0 


32.6 


26.3 


48.5 


51.1 


59.8 


63.0 


78 


79 


70.2 


34.0 


35.4 


33.1 


26.8 


49.2 


51.8 


60.6 


63.8 


79 


80 


71.1 


34.4 


35.9 


33.5 


27.3 


49.9 


52.5 


61.4 


64.6 


80 


81 


71.9 


34.9 


36.3 


34.0 


27.7 


50.5 


53.2 


62.2 


65.5 


81 


82 


72.8 


35.3 


36.8 


34.5 


28.2 


51.2 


53.9 


63.0 


66.3 


82 


83 


73.7 


35 8 


37.3 


34.9 


28.6 


51.8 


54.6 


63.8 


67.1 


83 


84 


74.6 


36 2 


37.7 


35.4 


29.1 


52.5 


55.3 


64.6 


68.0 


84 


85 


75.5 


36.7 


38.2 


35.8 


29.6 


53.1 


56.0 


65.4 


68.8 


85 


86 


76.4 


37.1 


38.6 


36.3 


30.0 


53.8 


56.6 


66.2 


69.7 


86 


87 


77.3 


37.5 


39.1 


36.8 


30.5 


54.5 


57.3 


67.0 


70.5 


87 


88 


78.2 


38.0 


39.5 


37.2 


31.0 


55.1 


58.0 


67.8 


71.3 


88 


89 


79.1 


38.4 


40.0 


37.7 


31.4 


55.8 


58.7 


68.5 


72.2 


89 


90 


79.9 


38.9 


40.4 


38.2 


31.9 


56.4 


59.4 


69.3 


73.0 


90 


91 


80.8 


39.3 


40.9 


38.6 


32.4 


57.1 


60.1 


70.1 


73.8 


91 


92 


81.7 


39.8 


41.4 


39.1 


32.8 


57.8 


60.8 


70.9 


74.7 


92 


93 


82.6 


40 2 


41 8 


39.6 


33.3 


58.4 


61.5 


71.7 


7V5 


93 


94 


83.5 


40.6 


42.3 


40.0 


33.8 


59.1 


62.2 


72.5 


76.3 


94 


95 


84.4 


41.1 


42.7 


40.5 


34.2 


59.7 


62.9 


73.3 


77.2 


95 


96 


85.3 


41.5 


43.2 


41.0 


34.7 


60.4 


63,6 


74.1 


78.0 


96 


97 


86.2 


42.0 


43.7 


41.4 


35.2 


61.1 


64.3 


74.9 


78.8 


97 


98 


87.1 


42.4 


44.1 


41.9 


35.6 


61.7 


65.0 


75.7 


79.7 


98 


99 


87.9 


42.9 


44.6 


42.4 


36.1 


62.4 


65.7 


76.5 


80.5 


99 


100 


88.8 


43.3 


45.0 


42.8 


36.6 


63.0 


66.4 


77.3 


81.3 


100 


101 


89.7 


43.8 


45 5 


43.3 


37.0 


63.7 


67.1 


78.1 


82.2 


101 


102 


90.6 


44.2 


46.0 


43.8 


37.5 


64.4 


67.8 


78.8 


83.0 


102 


103 


91.5 


44.7 


46.4 


44.2 


38.0 


65.0 


68.5 


79.6 


83.8 


103 


104 


92.4 


45.1 


46.9 


44.7 


38.5 


65.7 


69.1 


80.4 


84.7 


104 


105 


93.3 


45.5 


47.3 


45.2 


38.9 


66.4 


69.8 


81.2 


85.5 


105 


106 


94.2 


46.0 


47.8 


45.6 


39.4 


67.0 


70.5 


82.0 


86.3 


106 


107 


95.0 


46.4 


48.3 


46.1 


39.9 


67.7 


71.2 


82.8 


87.2 


107 


108 


95.9 


46.9 


48.7 


46.6 


40.3 


68.3 


71.9 


83.6 


88.0 


108 


109 


96.8 


47.3 


49.2 


47.0 


40.8 


69.0 


72.6 


84.4 


88.8 


109 


110 


97.7 


47.8 


49.6 


47.5 


41.3 


69.7 


73.3 


85.2 


89.7 


110 


111 


98.6 


48. 2 


50.1 


48.0 


41.7 


70.3 


74.0 


86.0 


90.5 


111 


112 


99.5 


48.7 


50.6 


48.4 


42.2 


71.0 


74.7 


86.8 


91.3 


112 


113 


100.4 


49.1 


51.0 


48.9 


42.7 


71.6 


75.4 


87.6 


92.2 


113 


114 


101.3 


49.0 


51.5 


49.4 


43.2 


72.3 


76.1 


88.4 


93.0 


114 


115 


102.2 


50.0 


51.9 


49.8 


43.6 


73.0 


76.8 


89.2 


93.9 


115 


116 


103.0 


50.5 


52.4 


50.3 


44.1 


73.6 


77.5 


90.0 


94.7 


116 


117 


103.9 


50.9 


52.9 


50.8 


44.6 


74.3 


78.2 


90.7 


95.5 


117 


118 


104.8 


51.4 


53.3 


51.2 


45.0 


75.0 


78.9 


91.5 


96.4 


118 


119 


105.7 


51.8 


53.8 


51.7 


45.5 


75.6 


79.6 


92.3 


97.2 


119 



90 






METHODS 


OF ANALYSIS 






[Chap. 


27 


Table 


1.— MUNSON AND 


WALKER'S TABLE.- 


-Continued. 










[Expressed in milligrams.] 










o 






m 




INVERT SUGAR 


LACTOSE 1 


MALTOSE 1 


Q 




O 

o 

p 




AND SUCROSE 










3 


Q 














u 


p 




ij 




3 

O 


3 

o 




O 




O 


o 


! 


"a 


■a 

H 
m 
o 


C4 


.4^ 

B 


S ^ 


6 


w 

q 


6 


6 




IS 

& 


P5 
S 


o 







o 


'^1 


8 

K 
6 


W 
6 


c5 


s 

W 

6 


o 
Pi 
«k 

C3 


120 


106.6 


52.3 


54.3 


62.2 


46.0 


76.3 


80.3 


93.1 


98.0 


120 


121 


107.5 


52.7 


64.7 


52.7 


46.5 


76.9 


81.0 


93.9 


08.9 


121 


122 


108.4 


53.2 


55.2 


53.1 


46.9 


77.6 


81.7 


94.7 


99.7 


122 


123 


109.3 


53.6 


55.7 


53.6 


47.4 


78.3 


82.4 


95.5 


100.5 


123 


124 


110.1 


54.1 


56.1 


54.1 


47.9 


78.9 


83.1 


96.3 


101.4 


124 


125 


111.0 


54.5 


66.6 


64.6 


48.3 


79.6 


83.8 


07.1 


102.2 


125 


126 


111.9 


55.0 


57.0 


66.0 


48.8 


80.3 


84.5 


07.9 


103.0 


126 


127 


112.8 


55.4 


57.5 


55.5 


49.3 


80.9 


85.2 


98.7 


103.9 


127 


128 


113.7 


55.9 


58.0 


55.9 


49.8 


81.6 


85.9 


99.4 


104.7 


128 


129 


114.6 


66.3 


58.4 


66.4 


60.2 


82.2 


86.6 


100.2 


105.5 


129 


130 


115.5 


56.8 


58.0 


56.9 


50.7 


82.0 


87.3 


101.0 


106.4 


130 


131 


116.4 


57.2 


59.4 


67.4 


61.2 


83.6 


88.0 


101.8 


107.2 


131 


132 


117.3 


57.7 


59.8 


67.8 


61.7 


84.2 


88.7 


102.6 


108.0 


132 


133 


118.1 


58.1 


60.3 


68.3 


52.1 


84.9 


89.4 


103.4 


108.0 


133 


134 


119.0 


68.6 


60.8 


68.8 


62.6 

( 


85.6 


00.1 


104.2 


100.7 


134 


135 


119.9 


69.0 


61.2 


69.3 


63.1 


86.2 


00.8 


105.0 


110.5 


135 


138 


120.8 


59.5 


61.7 


59.7 


53.6 


86.9 


91.6 


105.8 


111.4 


136 


137 


121.7 


60.0 


62.2 


60.2 


64.0 


87.6 


02.1 


106.6 


112.2 


137 


138 


122.6 


60.4 


62.6 


60.7 


64.6 


88.2 


02.8 


107.4 


113.0 


138 


139 


123.5 


60.0 


63.1 


61.2 


56.0 


88.9 


03.5 


108.2 


113.0 


139 


140 


124.4 


61.3 


63.6 


61.6 


55.5 


89.5 


94.2 


109.0 


114.7 


140 


141 


125.2 


61.8 


64.0 


62.1 


55.0 


00.2 


94.9 


109.8 


115.5 


141 


142 


126.1 


62.2 


64.6 


62.6 


66.4 


90.8 


95.6 


110.5 


116.4 


142 


143 


127.0 


62.7 


65.0 


63.1 


66.9 


91.5 


96.3 


111.3 


117.2 


143 


144 


127.9 


63.1 


65.4 


63.6 


67.4 


92.2 


97.0 


112.1 


118.0 


144 


145 


128.8 


63.6 


65.9 


64.0 


67.8 


92.8 


97.7 


112.0 


118.0 


145 


146 


129.7 


64.0 


66.4 


64.6 


68.3 


93.5 


98.4 


113.7 


119.7 


146 


147 


130.6 


64.6 


66.0 


66.0 


68.8 


94.2 


99.1 


114.6 


120.6 


147 


148 


131.5 


65.0 


67.3 


65.4 


69.3 


94.8 


99.8 


116.3 


121.4 


148 


149 


132.4 


65.4 


67.8 


65.9 


59.7 


95.5 


100.5 


116.1 


122.2 


149 


150 


133.2 


65.9 


68.3 


66.4 


60.2 


96.1 


101.2 


116.9 


123.0 


150 


151 


134.1 


66.3 


68.7 


66.9 


60.7 


96.8 


101.9 


117.7 


123.0 


151 


152 


135.0 


66.8 


69.2 


67.3 


61.2 


97.5 


102.6 


118.6 


124.7 


152 


153 


135.9 


67.2 


69.7 


67.8 


61.7 


98.1 


103.3 


119.3 


125.5 


153 


164 


136.8 


67.7 


70.1 


68.3 


62.1 


98.8 


104.0 


120.0 


126.4 


154 


155 


137.7 


68.2 


70.6 


68.8 


62.6 


99.6 


104.7 


120.8 


127.2 


155 


156 


138.6 


68.6 


71.1 


69.2 


63.1 


100.1 


105.4 


121.6 


128.0 


156 


157 


139.6 


69.1 


71.6 


69.7 


63.6 


100.8 


106.1 


122.4 


128.9 


157 


158 


140.3 


69.5 


72.0 


70.2 


64.1 


101.5 


106.8 


123.2 


129.7 


158 


159 


141.2 


70.0 


72.6 


70.7 


64.6 


102.1 


107.5 


124.0 


130.6 


159 


160 


142.1 


70.4 


73.0 


71.2 


65.0 


102.8 


108.2 


124.8 


131.4 


160 


161 


143.0 


70.9 


73.4 


71.6 


66.6 


103.4 


108.9 


125.6 


132.2 


161 


162 


143.9 


71.4 


73.9 


72.1 


66.0 


104.1 


109.6 


126.4 


133.0 


162 


163 


144.8 


71.8 


74.4 


72.6 


66.5 


104.8 


110.3 


127.2 


133.9 


163 


164 


145.7 


72.3 


74.9 


73.1 


66.9 


105.4 


111.0 


128.0 


134.7 


164 


165 


146.6 


72.8 


76.3 


73.6 


67.4 


106.1 


111.7 


128.8 


135.6 


165 


166 


147.5 


73.2 


75.8 


74.0 


67.9 


106.8 


112.4 


129.6 


136.4 


166 


167 


148.3 


73.7 


76.3 


74.5 


68.4 


107.4 


113.1 


130.3 


137.2 


167 


168 


149.2 


74.1 


76.8 


76.0 


68.9 


108.1 


113.8 


131.1 


138.0 


168 


169 


150.1 


74.6 


77.2 


76.6 


69.3 


108.8 


114.5 


131.9 


138.9 


169 


170 


151.0 


75.1 


77.7 


76.0 


69.8 


109.4 


115.2 


132.7 


139.7 


170 


171 


151.9 


75.5 


78.2 


76.4 


70.3 


110.1 


115.9 


133.5 


140.6 


171 


172 


152.8 


76.0 


78.7 


76.9 


70.8 


110.8 


116.6 


134.3 


141.4 


172 


173 


153.7 


76.4 


79.1 


77.4 


71.3 


111.4 


117.3 


135.1 


142.2 


173 


174 


154.6 


76.9 


79.6 


77.9 


71.7 


112.1 


118.0 


135.9 


143.0 


174 



VIII] FOODS AND FEEDING STUFFS 

27 Table 1.— Munson and Walt^er-s Table,— Continued. 

(Expressed in milligrams.] 



91 



^ 




Ui 




INVERT 


aiTOAH 










^^ 


o 
3 




m 
O 




AND SUCROSE 


LACTOSE 


MALTOSE 


O 

3 


o 




^ 










o 










"5 


c; 












a 

M 


^ 


5 


< 


o 


o 




O 




O 


a 



ta 




u 


D 


s 


(O 


_ 


w 


_ 


w 


o 

00 


b 


tf 


o 


H 


<A u 


S is 


o 


6 


6 


6 





o 

O 


a 

B. 
cu 
o 
u 


•y. 




> 

2 


.«. (0 

o 


to 3 
m 




6 


d 


«: 

6 




175 


155.5 


77.4 


80 1 


78.4 


72.2 


112.8 


118.7 


136.7 


143.9 


175 


176 


156.3 


77 8 


80 6 


78 8 


72.7 


113.4 


119,4 


137.5 


144.7 


176 


177 


157.2 


78 3 


81 


79 3 


73 2 


114.1 


120,1 


1.38.3 


145.5 


177 


178 


158 1 


78 8 


81 5 


79 8 


73.7 


114.8 


120.8 


139,1 


146.4 


178 


179 


159.0 


79.2 


82.0 


80.3 


74.2 


115.4 


121.5 


139.8 


147.2 


179 


180 


159 9 


79 7 


82 5 


80 8 


74.6 


116,1 


122.2 


140.6 


148.0 


180 


181 


160.8 


80 1 


82.9 


81 3 


75 1 


116.7 


122.9 


141 4 


148.9 


181 


182 


lfil.7 


80 6 


83.4 


81,7 


75.6 


117.4 


123.6 


142.2 


149.7 


182 


183 


162.6 


81 1 


83 9 


82.2 


76 1 


118.1 


124.3 


143.0 


150.5 


183 


184 


163.4 


81.5 


84.4 


82.7 


76.6 


118.7 


125.0 


143.8 


151.4 


184 


185 


164.3 


82.0 


84.9 


83.2 


77.1 


119.4 


125.7 


144.6 


1.52.2 


185 


186 


165 2 


82.5 


85.3 


83.7 


77 6 


120.1 


126.4 


145.4 


153.0 


186 


187 


166 1 


82 9 


85 8 


84 2 


78 


120.7 


127.1 


146 2 


1.53 9 


187 


188 


167 


83 4 


86 3 


84.6 


78.5 


121.4 


127.8 


147.0 


1.54.7 


188 


189 


167.9 


83.9 


86.8 


85.1 


79.0 


122.1 


128.5 


147.8 


155.5 


189 


190 


168 8 


84.3 


87.2 


85.6 


79.5 


122.7 


129.2 


148.6 


156.4 


190 


191 


169 7 


84 8 


87 7 


86 1 


80 


123.4 


129,9 


149 3 


1.57 2 


191 


192 


170 5 


85.3 


88.2 


86 6 


80.5 


124.1 


130.6 


150.1 


158.0 


192 


193 


171 4 


85 7 


88 7 


87.1 


81 


121.7 


131.3 


150.9 


158.9 


193 


194 


172.3 


86.2 


89.2 


87.6 


81.4 


125.4 


132.0 


151.7 


159.7 


194 


195 


173 2 


86.7 


89.6 


88.0 


81.9 


126.1 


132.7 


152.5 


160.5 


195 


196 


174 1 


87.1 


90 1 


88 5 


82.4 


126.7 


133.4 


1.53.3 


161.4 


198 


197 


175 


87 6 


90.6 


89 


82.9 


127,4 


134.1 


154.1 


162 2 


197 


198 


175 9 


88 1 


91 1 


89.5 


83 4 


128 1 


134.8 


154,9 


163.0 


198 


199 


176.8 


88.5 


91.6 


90.0 


83.9 


128.7 


135.5 


155.7 


163.9 


199 


200 


177 7 


89 


92.0 


90.5 


84.4 


129.4 


136.2 


156.5 


164.7 


200 


201 


178 5 


89 5 


92 5 


91.0 


84.8 


130.0 


136.9 


157.3 


165.5 


201 


202 


179 4 


89 9 


93 


91 4 


85.3 


130.7 


137.6 


158.1 


166.4 


202 


203 


ISO 3 


90 4 


93.5 


91 9 


85.8 


131.4 


138.3 


1.58.8 


167,2 


203 


204 


181.2 


90.9 


94.0 


92.4 


86.3 


132.0 


139.0 


159.6 


168.0 


204 


205 


182 1 


91.4 


94.5 


92.9 


86.8 


132.7 


139.7 


160.4 


168.9 


205 


206 


183,0 


91 8 


94.9 


93.4 


87.3 


133.4 


140 4 


161.2 


169.7 


206 


207 


183.9 


92 3 


95.4 


93.9 


87.8 


134.0 


141 1 


162.0 


170 5 


207 


208 


184 8 


92 8 


95.9 


94.4 


88.3 


134.7 


141.8 


162.8 


171.4 


208 


209 


185.6 


93.2 


96.4 


94.9 


88.8 


135.4 


142.5 


163.6 


172.2 


209 


210 


186 5 


93.7 


96.9 


95.4 


89.2 


136 


143.2 


164.4 


173.0 


210 


211 


187 4 


94.2 


97.4 


95.8 


89.7 


136 7 


143.9 


165.2 


173.8 


211 


212 


188.3 


94.6 


97,8 


96.3 


90.2 


137,4 


144,6 


166.0 


174.7 


212 


213 


189.2 


95 1 


98.3 


96 8 


90.7 


138,0 


145.3 


166.8 


175.5 


213 


214 


190.1 


95.6 


98.8 


97.3 


91.2 


138.7 


146.0 


167.5 


176.4 


214 


215 


191 


96.1 


99.3 


97.8 


91.7 


139.4 


146,7 


168.3 


177.2 


215 


216 


191 9 


96.5 


99 8 


98.3 


92.2 


140 


147.4 


169.1 


178.0 


218 


217 


192 8 


97.0 


100.3 


98.8 


92.7 


140.7 


148.1 


169.9 


178.9 


217 


218 


193 6 


97.5 


100.8 


99 3 


93.2 


141.4 


148.8 


170.7 


179.7 


218 


219 


194.5 


98.0 


101.2 


99.8 


93.7 


142.0 


149.5 


171.5 


180.5 


219 


220 


195 4 


98.4 


101.7 


100.3 


94.2 


142.7 


150.2 


172.3 


181.4 


220 


221 


196 3 


98 9 


102 2 


100.8 


94.7 


143.4 


1.50.9 


173.1 


182.2 


221 


222 


197 2 


99.4 


102.7 


101 2 


95 1 


144 


151.6 


173.9 


183 


222 


223 


198 1 


• 99 9 


103.2 


101.7 


95.6 


144.7 


152.3 


174.7 


183.9 


223 


224 


199.0 


100.3 


103.7 


102.2 


96.1 


145.4 


153.0 


175.5 


184.7 


224 


225 


199.9 


100.8 


104.2 


102 7 


96.6 


146.0 


153.7 


176.2 


185.5 


225 


226 


200 7 


101.3 


101.6 


103.2 


97.1 


146.7 


154.4 


177.0 


186.4 


228 


227 


201 6 


101 8 


105 1 


103 7 


97,6 


147.4 


155 1 


177.8 


187,2 


227 


228 


202.5 


102.2 


105.6 


104.2 


98 1 


148,0 


155 8 


178.6 


188.0 


228 


229 


203.4 


102.7 


106.1 


104.7 


98.6 


148.7 


156.5 


179.4 


188.8 


229 



92 
27 



Table 1. 



METHODS OF ANALYSIS 

-MUNSON AND WALKER'S TABLE. 
[Expressed in milligrams.] 



[Chap. 



-Continued. 



q 

3 


"a 
O 

« 


aj 
o 
o 

g 

9 
2. 

w 

m 

o 

« 


< 
o 




INVERT SUGAR 
AND SUCROSE 


LACTOSE 


MAITOSE 


q 

3 


o 

Q 

O 

P 
o 

K 

&4 


"3 
o 

a 

3 


"3 
o 

M 3 


1 


O 

q 


6 
1 


O 

K 
6 


O 

o 

K 
o 

m 
D 
O 
Pi 


t3 


o 


a 


h 


.^}4 tn 
o 


c" 


6 


c5 


o 


O 





230 


204.3 


103.2 


106.6 


105.2 


99,1 


149.4 


157.2 


180.2 


189.7 


230 


231 


205.2 


103.7 


107.1 


105.7 


99,6 


150.0 


157.9 


181.0 


190.5 


231 


232 


206.1 


104.1 


107.6 


106.2 


100.1 


150.7 


158.6 


181.8 


191.3 


232 


233 


207.0 


104.6 


108.1 


106.7 


100.6 


151.4 


159.3 


182.6 


192.2 


233 


234 


207.9 


105.1 


108.6 


107.2 


101.1 


152.0 


160.0 


183.4 


193.0 


234 


235 


208.7 


105.6 


109.1 


107.7 


101.6 


152.7 


160.7 


184.2 


193.8 


235 


236 


209.6 


106.0 


109.5 


108.2 


102.1 


153.4 


161.4 


184.9 


194.7 


236 


237 


210.5 


106.5 


110.0 


108,7 


102.6 


154.0 


162.1 


185 7 


195.5 


237 


23S 


211.4 


107.0 


110.5 


109.2 


103.1 


154.7 


162.8 


186.5 


196.3 


238 


239 


212.3 


107.5 


111.0 


109.6 


103.5 


155.4 


163.5 


187.3 


197.2 


239 


240 


213.2 


108.0 


111.5 


110.1 


104.0 


156.1 


164.3 


188.1 


198 


240 


241 


214.1 


108.4 


112.0 


110.6 


104.5 


156.7 


165.0 


188.9 


198.8 


241 


242 


215.0 


108.9 


112.5 


111.1 


105.0 


157.4 


165.7 


189.7 


199.7 


242 


243 


215.8 


109.4 


113.0 


111.6 


105.5 


158,1 


166.4 


190.5 


200.5 


243 


244 


216.7 


109.9 


113.5 


112.1 


106.0 


158.7 


167.1 


191.3 


201.3 


244 


245 


217.6 


110 4 


114.0 


112.6 


106.5 


159.4 


167.8 


192.1 


202.2 


245 


246 


218.5 


110.8 


114.5 


113.1 


107.0 


160.1 


168.5 


192.9 


203.0 


246 


247 


219.4 


111.3 


115.0 


113.6 


107.5 


160.7 


169.2 


193.6 


203.8 


247 


248 


220.3 


111.8 


115,4 


114.1 


108.0 


161.4 


169.9 


194.4 


204.7 


248 


249 


221.2 


112.3 


115.9 


114.6 


108.5 


162.1 


170.6 


195.2 


205.5 


249 


250 


222.1 


112.8 


116.4 


115.1 


109.0 


162,7 


171.3 


196.0 


206.3 


250 


251 


223.0 


113.2 


116.9 


115.6 


109.5 


163,4 


172.0 


196.8 


207.2 


251 


252 


223.8 


113.7 


117.4 


116.1 


110.0 


164,1 


172.7 


197.6 


208.0 


252 


253 


224.7 


114.2 


117.9 


116.6 


110.5 


164.7 


173.4 


198.4 


208.8 


253 


254 


225.6 


114.7 


118.4 


117.1 


111.0 


165.4 


174.1 


199.2 


209.7 


254 


255 


226.5 


115.2 


118.9 


117.6 


111.5 


166.1 


174.8 


200.0 


210.5 


255 


256 


227.4 


115.7 


119.4 


118.1 


112.0 


166.8 


175.5 


200.8 


211.3 


256 


257 


228.3 


116,1 


119.9 


118.6 


112,5 


167.4 


176 2 


201.6 


212.2 


257 


258 


229.2 


116.6 


120,4 


119.1 


113.0 


168.1 


176.9 


202.3 


213 


258 


259 


230.1 


117.1 


120.9 


119.6 


113.5 


168.8 


177.6 


203.1 


213.8 


259 


260 


231.0 


117.6 


121.4 


120.1 


114.0 


169.4 


178.3 


203.9 


214.7 


260 


261 


231.8 


118.1 


121.9 


120.6 


114.5 


170.1 


179 


204.7 


215.5 


261 


• 262 


232.7 


118.6 


122,4 


121.1 


115.0 


170,8 


179.8 


205.5 


216.3 


262 


263 


233.6 


119.0 


122.9 


121.6 


115,5 


171,4 


180.5 


206.3 


217.2 


263 


264 


234.5 


119.5 


123.4 


122.1 


116.0 


172.1 


181.2 


207.1 


218.0 


264 


265 


235.4 


120.0 


123.9 


122.6 


116.5 


172.8 


181.9 


207.9 


218.8 


265 


266 


236.3 


120.5 


124.4 


123.1 


117.0 


173.5 


182.6 


208.7 


219.7 


266 


267 


237.2 


121.0 


124.9 


123.6 


117.5 


174.1 


183.3 


209.5 


220.5 


267 


268 


238.1 


121.5 


125.4 


124.1 


118.0 


174.8 


184.0 


210.3 


221.3 


268 


269 


238.9 


122.0 


125.9 


124.6 


118.5 


175.5 


184.7 


211.0 


222.1 


269 


270 


239.8 


122.5 


126.4 


125.1 


119.0 


176.1 


185.4 


211.8 


223.0 


270 


271 


240.7 


122.9 


126.9 


125.6 


119.5 


176.8 


186.1 


212.6 


223.8 


271 


272 


241.6 


123.4 


127.4 


126.2 


120.0 


177.5 


186,8 


213.4 


224.6 


272 


273 


242.5 


123.9 


127.9 


126.7 


120.6 


178.1 


187.5 


214.2 


225 5 


273 


274 


243.4 


124.4 


128.4 


127.2 


121.1 


178.8 


188.2 


215.0 


226.3 


274 


275 


244.3 


124.9 


128.9 


127.7 


121.6 


179.5 


188.9 


215.8 


227.1 


275 


276 


245,2 


125.4 


129.4 


128.2 


122,1 


180.2 


189.6 


216.6 


228.0 


276 


277 


246.1 


125.9 


129.9 


128.7 


122,6 


180.8 


190.3 


217.4 


228 8 


277 


278 


246.9 


126.4 


130,4 


129.2 


123,1 


181.5 


191.0 


218.2 


229.6 


278 


279 


247.8 


126.9 


130.9 


129.7 


123.6 


182.2 


191.7 


218.9 


230.5 


279 


280 


248.7 


127.3 


131.4 


1.30.2 


124.1 


182.8 


192.4 


219.7 


231.3 


280 


281 


249.6 


127.8 


131 9 


130.7 


124.6 


183.5 


193 1 


220.5 


232.1 


281 


282 


250.5 


128.3 


132.4 


131.2 


125.1 


184.2 


193,9 


221.3 


233 


282 


283 


251.4 


128.8 


132.9 


131,7 


125.6 


184.8 


194.6 


222.1 


233.8 


283 


284 


252.3 


129.3 


133.4 


132,2 


126.1 


185.5 


195.3 


222.9 


234.6 


284 



VIII] 
27 



FOODS AND FEEDING STUFFS 

Table 1.— Munson and Walioer's Table.— Continued. 

[Expressed in milligrams.] 



93 



o 
5 


O 

o 


03 
O 

o 

p 

? 

» 

O 

US 

H 

» 


< 
o 

P 

g 


INVERT SUGAR 
AND 8UCR BE 


LACTOSE 


MALTOSE 


9 

3 


o 

a 

H 

o 

<a 

P 
O 
K 
P< 

8 


"3 
o 

s 

3 
o 


3 

o 

MS 


o 
d 


O 

W 

i 

w 

6 


o 
r: 

W 

6 


O 

i 

a 
o 


o 

o 

H 
O 

0) 

p 
O 

(^ 
P 


285 


253.2 


129.8 


133.9 


132.7 


126.6 


186.2 


196.0 


223.7 


235.5 


285 


286 


254.0 


130.3 


134.4 


133.2 


127.1 


186.9 


196.7 


224.5 


236.3 


286 


287 


254.9 


130.8 


134.9 


133.7 


127.6 


187.5 


197.4 


225.3 


237.1 


287 


288 


255.8 


131.3 


135.4 


134.3 


128.1 


188.2 


198.1 


226.1 


238.0 


288 


289 


256.7 


131.8 


135.9 


134.8 


128.6 


188.9 


198.8 


226.9 


238.8 


289 


290 


257.6 


132.3 


136.4 


135.3 


129.2 


189.5 


199.5 


227.6 


239.6 


290 


291 


258.5 


132.7 


136.9 


135.8 


129.7 


190.2 


200.2 


228.4 


240.5 


291 


292 


259.4 


133.2 


137.4 


136.3 


1.30.2 


190.9 


200.9 


229.2 


241.3 


292 


293 


260.3 


133.7 


137.9 


136.8 


130.7 


191.5 


201.6 


230.0 


242.1 


293 


294 


281.2 


134.2 


138.4 


137.3 


131.2 


192.2 


202.3 


230.8 


242.9 


294 


295 


262.0 


134.7 


138.9 


137.8 


131.7 


192.9 


203.0 


231.6 


243.8 


295 


296 


262.9 


135.2 


1.39.4 


138.3 


132.2 


193.6 


203.7 


232.4 


244.6 


296 


297 


263.8 


135.7 


140.0 


138.8 


132.7 


194.2 


204.4 


233.2 


245.4 


297 


298 


264.7 


136.2 


140.5 


139.4 


133.2 


194.9 


205.1 


234.0 


246.3 


298 


299 


265.6 


136.7 


141.0 


139.9 


133.7 


195.6 


205.8 


234.8 


247.1 


299 


300 


266.5 


137 2 


141.5 


140.4 


134.2 


196.2 


206.6 


235.5 


247.9 


300 


301 


267.4 


137.7 


142.0 


140.9 


134.8 


196.9 


207.3 


236.3 


248.8 


301 


302 


268.3 


138.2 


142.5 


141.4 


135.3 


197.6 


208.0 


237.1 


249.6 


302 


303 


269.1 


138,7 


143.0 


141.9 


135.8 


198.3 


208.7 


237.9 


250.4 


303 


304 


270.0 


139.2 


143.5 


142.4 


136.3 


198.9 


209.4 


238.7 


251.3 


304 


305 


270.9 


139.7 


144.0 


142.9 


136.8 


199.6 


210.1 


239,5 


252.1 


305 


306 


271.8 


140.2 


144.5 


143.4 


137.3 


200.3 


210.8 


240.3 


252.9 


306 


807 


272.7 


140.7 


145.0 


144.0 


137.8 


201.0 


211.5 


241.1 


253.8 


307 


308 


273.6 


141.2 


145.5 


144.5 


138.3 


201.6 


212.2 


241.9 


254.6 


308 


309 


274.5 


141.7 


146.1 


145.0 


138.8 


202.3 


212.9 


242.7 


255.4 


309 


310 


275.4 


142.2 


146.6 


145.5 


139.4 


203.0 


213.7 


243.5 


256.3 


310 


311 


276.3 


142.7 


147,1 


146.0 


139.9 


203.6 


214.4 


244.2 


257.1 


311 


312 


277.1 


143.2 


147.6 


146.5 


140.4 


204.3 


215.1 


245.0 


257.9 


312 


313 


278.0 


143.7 


148.1 


147.0 


140.9 


205.0 


215.8 


245.8 


258.8 


313 


314 


278.9 


144.2 


148.6 


147.6 


141.4 


205.7 


216.5 


246.6 


259.6 


314 


315 


279.8 


144.7 


149.1 


148.1 


141.9 


206.3 


217.2 


247.4 


260.4 


315 


316 


280.7 


145.2 


149.6 


148.6 


142.4 


207.0 


217.9 


248.2 


261.2 


316 


317 


281.6 


145.7 


150.1 


149.1 


143.0 


207.7 


218.6 


249.0 


262.1 


317 


318 


282.5 


146.2 


150.7 


149.6 


143.5 


208.4 


219.3 


249.8 


262.9 


318 


319 


283.4 


146.7 


151.2 


150.1 


144.0 


209.0 


220.0 


250.6 


263.7 


31-9 


320 


284.2 


147.2 


151.7 


150.7 


144.5 


209.7 


220.7 


251.3 


264.6 


320 


321 


285.1 


147.7 


152.2 


151.2 


145.0 


210.4 


221.4 


2.52.1 


265.4 


321 


322 


286.0 


148.2 


152.7 


151.7 


145.5 


211.0 


222.2 


252.9 


266.2 


322 


323 


286.9 


148.7 


153.2 


152.2 


146.0 


211.7 


222.9 


253.7 


267.1 


323 


324 


287.8 


149.2 


153.7 


152.7 


146.6 


212.4 


223.6 


254.5 


267.9 


324 


325 


288.7 


149.7 


154.3 


153.2 


147.1 


213.1 


224.3 


255.3 


268.7 


325 


326 


289.6 


150.2 


154.8 


153.8 


147.6 


213.7 


225.0 


256.1 


269.6 


326 


327 


290.5 


150.7 


1.55.3 


154.3 


148.1 


214.4 


225.7 


256.9 


270.4 


327 


328 


291.4 


151.2 


155.8 


154.8 


148.6 


215.1 


226.4 


257.7 


271.2 


328 


329 


292.2 


151.7 


156.3 


155.3 


149.1 


215.8 


227.1 


258.5 


272.1 


329 


330 


293.1 


152.2 


156.8 


155.8 


149.7 


216.4 


227.8 


259.3 


272.9 


330 


331 


294.0 


152.7 


157.3 


156.4 


150 2 


217.1 


228.5 


260.0 


273,7 


331 


332 


294.9 


153.2 


157.9 


156.9 


150.7 


217.8 


229.2 


260.8 


274.6 


332 


333 


295.8 


153.7 


158.4 


157.4 


151.2 


218.4 


230.0 


261.6 


275 4 


333 


334 


296.7 


154.2 


158.9 


157.9 


151.7 


219.1 


230.7 


262.4 


276.2 


334 


335 


297.6 


154.7 


159.4 


158.4 


152.3 


219.8 


231.4 


263.2 


277.0 


335 


336 


2fl8.5 


155.2 


159.9 


1.59.0 


152.8 


220.5 


232.1 


264.0 


277.9 


336 


337 


299.3 


155.8 


160.5 


159 5 


153.3 


221.1 


232.8 


264.8 


278.7 


337 


338 


300.2 


156.3 


161.0 


160.0 


153.8 


221.8 


233.5 


265.6 


279.5 


338 


339 


301.1 


156.8 


161.5 


160.5 


154.3 


222.5 


234.2 


266.4 


280.4 


339 



94 
27 



METHODS OF ANALYSIS 

Table 1. — Munson and Walker-s Table.— Continued. 

[Expressed in milligrams.) 



[Chap. 



6 




"5 




INVERT SUGAR 1 


LACTOSE 1 


MALTOSE 1 


O 




o 




AND SUCROSE 










5 


o 




p 




"5 


"d 










o 


CI 




o 


m 


o 


O 




o 




O 


o 






•^ 


< 














p 


X 



9 

u 


H 




t. at 
bC bl 

3 






W 




te 


o 


01 

o 


a 
p. 


03 

o 
es 

P. 
a 
a 


09 


is 

2 to 

M 3 


O 


q 
1 


6 




GO 
P 

o 

£ 


i 


8 


> 


o 


« 


o 


6 


6 


6 


p 


340 


302.0 


157.3 


182.0 


181.0 


154.8 


223.2 


2.34.9 


267.1 


281.2 


340 


341 


302.9 


157.8 


162.5 


161.6 


155.4 


223.8 


235.8 


267.9 


282.0 


341 


342 


303.8 


158.3 


163.1 


162.1 


155.9 


224.5 


236.3 


268.7 


282.9 


343 


343 


304.7 


158.8 


163.6 


162.6 


156.4 


225.2 


237.0 


269.5 


283.7 


343 


344 


305.6 


159.3 


184.1 


183.1 


156.9 


225.9 


237.8 


270.3 


284.5 


344 


345 


308.5 


159.8 


184.6 


163.7 


157.5 


226.5 


238.5 


271.1 


285.4 


345 


346 


307.3 


160.3 


165.1 


164.2 


158.0 


227.2 


2.39.2 


271.9 


288.2 


346 


347 


308.2 


160.8 


165.7 


164.7 


158.5 


227.9 


239,9 


272.7 


2.87.0 


347 


348 


309.1 


161.4 


166.2 


185.2 


159.0 


228.5 


240.6 


273.5 


287.9 


348 


349 


310.0 


161.9 


186.7 


165.7 


159.5 


229.2 


241.3 


274.3 


288.7 


349 


3.'50 


310.9 


162 4 


167.2 


166.3 


160.1 


229.9 


242.0 


275.0 


289.5 


350 


351 


311.8 


162.9 


167.7 


168.8 


100.6 


230.6 


242.7 


275.8 


290 4 


351 


352 


312.7 


163.4 


188.3 


187.3 


161.1 


231.2 


243.4 


278.6 


291.2 


352 


353 


313.6 


163.9 


168.8 


167.8 


161.6 


231.9 


244.1 


277.4 


292.0 


353 


354 


314.4 


164.4 


169.3 


168.4 


182.2 


232.6 


244.8 


278.2 


292,8 


354 


355 


315.3 


164.9 


169.8 


168.9 


182.7 


233.3 


245.6 


279.0 


293.7 


355 


356 


316.2 


165.4 


170.4 


189.4 


163.2 


233.9 


246.3 


279.8 


294.5 


356 


357 


317.1 


186 


170.9 


170.0 


163.7 


234.6 


247.0 


280.6 


295.3 


357 


358 


318.0 


166.5 


171.4 


170.5 


184.3 


235.3 


247.7 


281.4 


298 2 


358 


359 


318.9 


167.0 


171.9 


171.0 


184.8 


236.0 


248.4 


282.2 


297.0 


359 


360 


319.8 


167 5 


172.5 


171.5 


165.3 


236.7 


249.1 


282.9 


297.8 


360 


361 


320.7 


168.0 


173.0 


172.1 


185.8 


237.3 


249.8 


283.7 


298.7 


361 


362 


321.8 


168.5 


173.5 


172.8 


166.4 


238.0 


250.5 


284.5 


299.5 


362 


363 


322.4 


169.0 


174.0 


173.1 


166.9 


238.7 


251.2 


285.3 


300.3 


363 


364 


323.3 


189.6 


174.6 


173.7 


167.4 


239.4 


252.0 


286.1 


301.2 


364 


365 


324.2 


170.1 


175.1 


174.2 


167.9 


240.0 


252.7 


286.9 


302,0 


365 


368 


325.1 


170.6 


175.6 


174.7 


168.5 


240.7 


253.4 


287.7 


302.8 


386 


367 


326.0 


171.1 


176.1 


175.2 


189.0 


241.4 


254.1 


288.5 


303.6 


367 


368 


326.9 


171.6 


176.7 


175.8 


169.5 


242.1 


254.8 


289.3 


304.5 


368 


369 


327.8 


172.1 


177.2 


176.3 


170.0 


242.7 


255.5 


290.0 


305.3 


369 


370 


328.7 


172.7 


177.7 


176.8 


170.6 


243.4 


2.56.2 


290.8 


306.1 


370 


371 


329.5 


173.2 


178.3 


177.4 


171.1 


244.1 


256.9 


291.6 


307 


371 


372 


330 4 


173.7 


178.8 


177.9 


171,8 


244.8 


2,57.7 


292.4 


307.8 


372 


373 


331.3 


174.2 


179.3 


178.4 


172.2 


245.4 


258.4 


293.2 


308.6 


373 


374 


332.2 


174.7 


179.8 


179.0 


172.7 


246.1 


259.1 


294.0 


309.5 


374 


375 


333.1 


175.3 


180 4 


179.5 


173.2 


246.8 


259.8 


294.8 


310.3 


375 


376 


334.0 


175.8 


180.9 


180.0 


173.7 


247.5 


260.5 


295.6 


311.1 


376 


377 


334.9 


176.3 


181.4 


180.6 


174.3 


248 1 


281.2 


296.4 


312.0 


377 


378 


335.8 


176.8 


182.0 


181.1 


174.8 


248.8 


261.9 


297.2 


312.8 


378 


379 


336.7 


177.3 


182.5 


181.6 


175.3 


249.5 


262.6 


297.9 


313.6 


379 


380 


337.5 


177.9 


183.0 


182.1 


175.9 


250.2 


263.4 


298.7 


314.5 


380 


381 


338 4 


178.4 


183.6 


182.7 


176,4 


2.50.8 


264.1 


299.5 


315.3 


381 


382 


339.3 


178.9 


184.1 


183.2 


176.9 


251.5 


264.8 


300.3 


316.1 


382 


383 


340.2 


179.4 


184.6 


183.8 


177.5 


252.2 


285.5 


301.1 


316.9 


383 


384 


341.1 


180.0 


185.2 


184.3 


178.0 


252.9 


266.2 


301.9 


317.8 


384 


385 


342.0 


180.5 


185.7 


184.8 


178.5 


253.6 


266.9 


302.7 


318.6 


385 


386 


342.9 


181. 


186.2 


185.4 


179.1 


254.2 


267.8 


303.5 


319.4 


389 


387 


343.8 


181.5 


186.8 


185.9 


179.6 


254.9 


268.3 


304.2 


320.3 


387 


388 


344.6 


182.0 


187.3 


186.4 


180.1 


255.6 


269.0 


305.0 


321.1 


388 


389 


345.5 


182,6 


187.8 


187.0 


180.8 


256.3 


269.8 


305.8 


321.9 


389 


390 


346.4 


183.1 


188.4 


187.5 


181.2 


256.9 


270.5 


306.6 


322.8 


390 


391 


347 3 


183.6 


188.9 


188.0 


181.7 


257.6 


271.2 


307.4 


323.6 


391 


392 


348 2 


184.1 


189.4 


188.8 


182.3 


258.3 


271.9 


308. 2 


324.4 


392 


393 


349.1 


184.7 


190.0 


189.1 


182.8 


259.0 


272.6 


309.0 


325 2 


393 


394 


350.0 


185.2 


190.5 


189.7 


183.3 


259.6 


273.3 


309.8 


329.1 


394 



VIII] 






FOODS AND 


FEEDING STUFFS 






95 


27 


Table 1.— 


MUNSON AND 


WALKER'S TABLE- 


-Continued. 












[Expressed in milligrams 


1 








3 


3 
o 

(S 

a. 
o 
o 


m 
m 
O 
o 

P 

o 

H 

O 
K 
H 

Q 


K 
-<i 
O 
P 
m 

H 

« 

> 

g 


INVERT SUGAR 
AND SUCROSE 


LACTOSE 


MALTOSE 


9 

3 


o 

Q 

O 
m 

d 

o 

K 
o 


1 

3 
o 


'S 
1 

St; 

M 3 


d 

a 
K 

6 


O 

w 
5 
t| 
6 


i 

6 


O 

w 

O 
K 

6 


o 

a 
k 


ai 

O 
O 
K 
0) 
P 
o 


395 


350.9 


185.7 


191.0 


190.2 


183.9 


260.3 


274.0 


310.6 


326.9 


395 


306 


351,8 


186.2 


191.6 


190.7 


184.4 


261.0 


274 7 


311.4 


327 7 


396 


397 


352.6 


186.8 


192 1 


191.3 


184.9 


261.7 


275.5 


312 1 


328.6 


397 


398 


353.5 


187.3 


192.7 


191 8 


185.5 


262.3 


276.2 


312.9 


329.4 


398 


399 


354.4 


187.8 


193.2 


192.3 


186.0 


263.0 


276.9 


313.7 


330.2 


399 


400 


355.3 


188.4 


193.7 


192.9 


186.5 


263.7 


277.6 


314.5 


331 1 


400 


401 


356.2 


188.9 


194.3 


193.4 


187.1 


264.4 


278.3 


315 3 


331.9 


401 


402 


357.1 


189,4 


194.8 


194,0 


187.6 


265.0 


279.0 


316 1 


3.32.7 


402 


403 


358.0 


189,9 


195,4 


194,5 


188,1 


265.7 


279 7 


318.9 


333.8 


403 


404 


358.9 


190.5 


195.9 


195.0 


188.7 


266.4 


280.4 


317.7 


334.4 


401 


405 


3.59.7 


191.0 


198.4 


195.6 


189.2 


267.1 


281.1 


318.5 


335 2 


405 


408 


360.6 


191.5 


197.0 


198.1 


189.8 


267 8 


281 9 


319,2 


3.36 


406 


407 


351.5 


192 1 


197.5 


196.7 


193.3 


268.4 


282 6 


320,0 


3.36 9 


407 


408 


362.4 


192,6 


198.1 


197.2 


190,8 


269 1 


283,3 


320,8 


337.7 


408 


409 


363.3 


193,1 


198.6 


197.7 


191.4 


269.8 


284.0 


321.6 


338.5 


409 


410 


361.2 


193,7 


199.1 


198.3 


191.9 


270.5 


284.7 


322.4 


339.4 


410 


411 


365.1 


194 2 


199.7 


198.8 


192.5 


271.2 


285,4 


323 2 


340,2 


411 


412 


366.0 


194,7 


200.2 


199.4 


193.0 


271,8 


286 2 


324,0 


341 


412 


413 


366.9 


195.2 


203.8 


199.9 


193.5 


272.5 


286,9 


324,8 


341 9 


413 


414 


367.7 


195,8 


201.3 


200.5 


194.1 


273.2 


287.6 


325.6 


342.7 


414 


415 


368.6 


196.3 


201.8 


201.0 


194.6 


273.9 


288.3 


326.3 


343.5 


415 


416 


360.5 


196.8 


202.4 


201.6 


195.2 


274.6 


289.0 


327.1 


344.4 


416 


417 


370.4 


197.4 


202,9 


202.1 


195.7 


275.2 


289.7 


327.9 


345.2 


417 


418 


371.3 


197 9 


203.5 


202.6 


196.2 


275.9 


290.4 


328,7 


346.0 


418 


419 


372.2 


198.4 


204.0 


203.2 


196.8 


276.6 


291.2 


329.5 


346.8 


419 


420 


373.1 


199.0 


204,6 


203.7 


197 3 


277 3 


291.9 


330,3 


347,7 


420 


421 


374 


199 5 


20i 1 


204.3 


197.9 


277.9 


292.6 


331 1 


348.5 


421 


422 


374 8 


200.1 


205.7 


204,8 


198 4 


278.6 


293 3 


331,9 


349,3 


422 


423 


375.7 


201.6 


206.2 


205,4 


193.9 


279.3 


294,0 


332,7 


3.50,2 


423 


424 


376.6 


201.1 


208.7 


205.9 


199.5 


280,0 


294.7 


333.4 


351.0 


424 


425 " 


377.5 


201.7 


207.3 


206.5 


200.0 


280.7 


295.4 


334.2 


351.8 


425 


426 " ' 


378.4 


202.2 


207.8 


207.0 


290.6 


281.3 


296.2 


335.0 


352 7 


426 


427 f;3 


379.3 


202.8 


208.4 


207.6 


201.1 


282.0 


296.9 


3.35.8 


353 5 


427 


428 


380.2 


203.3 


208.9 


20S.1 


201.7 


282.7 


297.6 


3.36.6 


354,3 


428 


429 


381.1 


203.8 


209.5 


208.7 


202.2 


283 4 


298.3 


337.4 


355.1 


429 


430 


382.0 


204.4 


210 


209.2 


202.7 


284.1 


299.0 


3.38.2 


356 


430 


431 


382.8 


204.9 


210 6 


209 8 


203.3 


284.7 


299.7 


3.39.0 


356,8 


431 


432 


383.7 


20i.5 


211 1 


210.3 


203.8 


285 4 


300 5 


3.39,7 


357,6 


432 


433 


384.6 


206.0 


211.7 


210,9 


201.4 


286,1 


301.2 


340,5 


3.58,5 


433 


434 


385.5 


206.5 


212.2 


211.4 


204.9 


280.8 


301.9 


341.3 


359.3 


434 


435 


386.4 


207.1 


212.8 


212.0 


205.5 


287.5 


302.6 


342.1 


360.1 


435 


436 


3S7.3 


207,6 


213.3 


212.5 


203.0 


288.1 


303.3 


342.9 


361.0 


436 


437 


388.2 


208 2 


213.9 


213,1 


208 6 


2SS.8 


304,0 


343.7 


3G1.8 


437 


438 


389,1 


208,7 


214,4 


213,6 


207.1 


289.5 


301.7 


344 5 


362 6 


438 


439 


390.0 


209.2 


215.0 


214.2 


207.7 


290.2 


305.5 


345.3 


363.4 


439 


440 


391.8 


209.8 


215.5 


214.7 


208.2 


290.9 


306 2 


346.1 


364 3 


440 


441 


391.7 


210 3 


216 1 


215 3 


20S.8 


291 5 


303 9 


346.8 


365 1 


441 


442 


392.6 


210 9 


216,6 


215.8 


209.3 


292.2 


307,6 


347 6 


365 9 


442 


443 


393.5 


211.4 


217.2 


216.4 


209.9 


292.9 


308 3 


348.4 


366,8 


443 


444 


394.4 


212.0 


217.8 


218.9 


210.4 


293.6 


309.0 


349.2 


367,6 


444 


445 


395.3 


212.5 


218 3 


217.5 


211.0 


294,2 


309.7 


350.0 


368,4 


445 


446 


396 2 


213 1 


218.9 


218 


211,5 


294 9 


310.5 


3.50 8 


369.3 


446 


447 


397 1 


213 6 


219,4 


218.6 


212 1 


295 6 


311 2 


351.6 


370 1 


447 


44S 


397 9 


214 1 


220.0 


219 1 


212 6 


298,3 


311.9 


352.4 


370 9 


448 


449 


398.8 


214.7 


220.5 


219.7 


213.2 


297.0 


312.6 


353.2 


371.7 


449 



96 
27 



METHODS OF ANALYSIS 

Table 1.— Munson and Walker's Table.— Continued. 

[Expressed in milligrams.] 



[Chap. 



o 

3 


3 

o 

PS 

m 

t 
o 


"a 
m 

o 

& 

o 

Ed 

m 

c 
« 


< 
a 
p 

> 

g 


INVERT SUG.A.B 
AND SUCROSE 


LACTOSE 


MALTOSE 


q 

3 


o 

Q 

K 

C 
m 
P 
O 
K 
P. 
& 
o 


O 

a 

3 
o 


O 


q 
6 


O 

o 

1 
6 


6 


O 

w 

q 

1 
6 


o 

a 
o 

p 
o 

a 

0. 

p 

o 


450 


399.7 


215.2 


221.1 


220.2 


213.7 


297.6 


313.3 


353.9 


372.6 


450 


451 


400.6 


215.8 


221.6 


220.8 


214.3- 


298.3 


314.0 


354.7 


373.4 


451 


452 


401.5 


216.3 


222.2 


221.4 


214.8 


299.0 


314.7 


355.5 


374.2 


452 


453 


402.4 


216.9 


222.8 


221.9 


215.4 


299.7 


315.5 


356.3 


375.1 


453 


454 


403.3 


217.4 


223.3 


222.5 


215.9 


300.4 


316.2 


357.1 


375.9 


454 


455 


404.2 


218.0 


223.9 


223.0 


216.5 


301.1 


316.9 


357.9 


376.7 


455 


456 


405.1 


218.5 


224 4 


223.6 


217.0 


301.7 


317.6 


358.7 


377.6 


456 


457 


405.9 


219.1 


225.0 


224.1 


217.6 


302.4 


318.3 


359.5 


378.4 


457 


458 


406.8 


219.6 


225.5 


224.7 


218.1 


303.1 


319.0 


360.3 


379.2 


458 


459 


407.7 


220.2 


226.1 


225.3 


218.7 


303.8 


319.8 


361.0 


380.0 


459 


460 


408.6 


220.7 


226.7 


225.8 


219.2 


304.5 


320.5 


361.8 


380.9 


460 


461 


409.5 


221.3 


227.2 


226.4 


219.8 


305.1 


321.2 


362.6 


381.7 


461 


462 


410.4 


221.8 


227.8 


■226.9 


220.3 


305.8 


321.9 


363.4 


382.5 


462 


463 


411.3 


222.4 


228.3 


227.5 


220.9 


306.5 


322.6 


364.2 


383.4 


463 


464 


412.2 


222.9 


228.9 


228.1 


221.4 


307.2 


323.4 


365.0 


384.2 


464 


465 


413.0 


223.5 


229.5 


228.6 


222.0 


307.9 


324.1 


365.8 


385.0 


465 


466 


413.9 


224.0 


230.0 


229.2 


222.5 


308.6 


324.8 


366.6 


385.9 


466 


467 


414.8 


224.6 


230.6 


229.7 


223.1 


309.2 


325.5 


367.3 


386.7 


467 


468 


415.7 


225,1 


231.2 


230.3 


223.7 


309.9 


326.2 


368.1 


387.5 


468 


469 


416.6 


225.7 


231.7 


230.9 


224.2 


310.6 


326.9 


368.9 


388.3 


469 


470 


417.5 


226.2 


232.3 


231.4 


224.8 


311.3 


327.7 


369.7 


389.2 


470 


471 


418.4 


226.8 


232.8 


232.0 


225.3 


312.0 


328.4 


370.5 


390.0 


471 


472 


419.3 


227.4 


233.4 


232.5 


225.9 


312.6 


329.1 


371.3 


390.8 


472 


473 


420.2 


227.9 


234.0 


2.33.1 


226.4 


313.3 


329.8 


372.1 


391.7 


473 


474 


421.0 


228.5 


234.5 


233.7 


227.0 


314.0 


330.5 


372.9 


392.5 


474 


475 


421.9 


229.0 


235.1 


234.2 


227.6 


314.7 


331.3 


373.7 


393.3 


475 


476 


422.8 


229.6 


235.7 


234.8 


228.1 


315.4 


332.0 


374.4 


394.2 


476 


477 


423.7 


230.1 


236.2 


235.4 


228.7 


316.1 


332.7 


375.2 


395.0 


477 


478 


424.6 


230.7 


236.8 


235.9 


229.2 


316.7 


333.4 


376.0 


395.8 


478 


479 


425.5 


231.3 


237.4 


236.5 


229.8 


317.4 


334.1 


376.8 


396.6 


479 


480 


426.4 


231.8 


237.9 


237.1 


230.3 


318.1 


334.8 


377.6 


397.5 


480 


481 


427.3 


232.4 


238.5 


237.6 


230.9 


318.8 


335.6 


378.4 


398.3 


481 


482 


428.1 


232.9 


239.1 


238.2 


231.5 


319.5 


336 3 


379.2 


399.1 


482 


483 


429.0 


233.5 


239.6 


238.8 


232.0 


320.1 


337.0 


380.0 


400.0 


483 


484 


429.9 


234.1 


240.2 


239.3 


232.6 


320.8 


337.7 


380.7 


400.8 


484 


485 


430.8 


2,34.6 


240.8 


239.9 


233.2 


321.5 


338.4 


381.5 


401.6 


485 


486 


431.7 


235.2 


241.4 


240.5 


233.7 


322.2 


3.39.1 


382.3 


402.4 


486 


487 


4.32 6 


2.35.7 


241.9 


241.0 


234.3 


322.9 


339.9 


383.1 


403.3 


487 


488 


433.5 


236.3 


242.5 


241.6 


234.8 


323.6 


340.6 


383.9 


404.1 


488 


489 


434.4 


236.9 


243.1 


242.2 


235.4 


324.2 


341.3 


384.7 


404.9 


489 


490 


435.3 


237.4 


243.6 


242.7 


236.0 


324.9 


342.0 


385.5 


405.8 


490 



28 



//. A. H. Low Volumetric Method, Modified.'' — Tentative. 



Standard ihwsulphate solution. — Prepare a solution of sodium thiosulphate 
containing 19 grams of pure crystals in 1 liter. Weigh accurately about 0.2 
gram of pure copper foil and place in a flask of 250 cc. capacity. Dissolve by warming 
with 5 cc. of a mixture of equal volumes of strong nitric acid and water. Dilute 
to 50 cc, boil to expel the red fumes, add 5 cc. of strong bromin water, and boil 



VIII] FOODS AND FEEDING STUFFS 97 

until the bromin is completely driven off. Remove from the heat and add a slight 
excess of strong ammonium hydroxid (about 7 cc. is required). Again boil until 
the excess of ammonia is expelled, as shown by a change of color of the liquid, 
and a partial precipitation. Then add a slight excess of strong acetic acid (3 or 4 
cc. of 80% acid) and boil for a minute. Cool to room temperature and add 10 cc. 
of 30% potassium iodid solution. Titrate at once with the thiosulphate solution 
until the brown tinge has become weak, then add sufficient starch indicator [VII, 
3 (a)] to produce a marked blue coloration. Continue the titration cautiously 
until the color due to free iodin has entirely vanished. The blue color changes to- 
ward the end to a faint lilac. If at this point the thiosulphate be added drop by drop 
and a little time allowed for complete reaction after each addition, there is no diffi- 
culty in determining the end point within a single drop. One cc. of the thiosulphate 
solution will be found to correspond to about 0.005 gram of copper. 



29 



DETERMINATION. 



After washing the precipitated cuprous oxid, cover the Gooch with a watch 
glass and dissolve the oxid by means of 5 cc. of warm nitric acid (1 to 1) poured under 
the watch glass with a pipette. Catch the filtrate in a 250 cc. flask, wash the 
watch glass and Gooch free of copper, using about 50 cc. of water. Boil to expel 
red fumes, add 5 cc. of bromin water, boil off the bromin, and proceed exactly as 
in 28. 

30 ///. Volumetric Permanganate Method. — Tentative. 

Filter and wash the cuprous oxid as directed under 25. Transfer the asbestos 
film to the beaker, add about 30 cc. of hot water, and beat the precipitate and asbes- 
tos thoroughly. Rinse the crucible with 50 cc. of a hot saturated solution of ferric 
sulphate in 20% sulphuric acid, receiving the rinsings in the beaker containing the 
precipitate. After the cuprous oxid is dissolved, wash the solution into a large 
Erlenmeyer flask and immediately titrate with a standard solution of potassium 
permanganate, 1 cc. of which should be equivalent to 0.010 gram of copper. Stand- 
ardize this solution by making 6 or more determinations with the same sugar solu- 
tion, titrating one half of the precipitates obtained, and determining the copper in 
the others by electrolysis. The average weight of copper obtained by electrolysis, 
divided by the average number of cc. of permanganate solution required for the 
titrations, gives the weight of copper equivalent to 1 cc. of the standard perman- 
ganate solution. A solution standardized with iron or oxalic acid will give too low 
a result. 

31 IV. Electrolytic Deposition from Sulphuric Acid Solution. — Tentative. 

Filter the cuprous oxid in a Gooch, wash the beaker and the precipitate thoroughly 
with hot water without transferring the precipitate to the filter. Wash the asbestos 
film and the adhering cuprous oxid into the beaker by means of hot dilute nitric acid. 
After the copper is all in solution, refilter through a thin film of asbestos in a Gooch 
and wash thoroughly with hot water. Add 19 cc. of sulphuric acid (1 to 4), and 
evaporate the filtrate on the steam bath until the copper salt has largely crystal- 
lized. Heat carefully on a hot plate or over asbestos until the evolution of white 
fumes shows that the excess of nitric acid is removed. Add 8-10 drops of nitric acid 
(sp. gr. 1.42) and rinse into a 100-125 cc. platinum dish. Deposit the copper by 



98 METHODS OF ANALYSIS [Chap. 

electrolysis. Wash thoroughly with water, then break the current, wash with alco- 
hol and ether successively, dry at about 50°C.^ and weigh. If preferred, the elec- 
trolysis can be conducted in a beaker, the copper being deposited upon a weighed 
platinum electrode. 

32 V. Electrolytic Deposition from Sulphuric and Nitric Acid S ilition. — Tentative. 

Filter and wash as directed under 31 . Transfer the asbestos film from the cru- 
cible to the beaker by means of a glass rod and rinse the crucible with about 30 cc. 
of a boiling mixture of dilute sulphuric and nitric acids, containing 65 cc. of sul- 
phuric acid (sp. gr. 1.84) and 50 cc. of nitric acid (sp. gr. 1.42) per liter. Heat and 
agitate until solution is complete; filter and electrolyze as under 31 . 

33 VI. Electrolytic Deposition from Nitric Acid Sdution. — Tentative. 

Filter and wash as directed under 31. Transfer the asbestos film and adhering 
oxid to the beaker. Dissolve the oxid still remaining in the crucible by means of 
2 cc. of nitric acid (so. gr. 1.42), adding it with a pipette and receiving the solution 
in the beaker containing the asbestos film. Rinse the crucible with a jet of water, 
allowing the rinsings to flow into the beaker. Heat the contents of the beaker until 
the copper is all in solution, filter, dilute the filtrate to a volume of 100 cc. or more, 
and electrolyze. When a nitrate solution is electrolyzed, the first washing of the 
deposit should be made with water acidulated with sulphuric acid, in order to remove 
all the nitric acid before the current is interrupted. 

34 VII. Reduction in Hydrogen. — Tentative. 

Deposit an asbestos film on a perforated platinum disc or cone contained in a 
hard glass filtering tube, wash free from loose fibers, dry and weigh. Through this 
tube, previously moistened, filter the cuprous oxid immediately, using suction. 
Transfer the cuprous oxid to the tube through a removable funnel, and wash thor- 
oughly with hot water, alcohol and ether successively. After drying, connect the 
tube with a supply of dry hydrogen, heat gently until the cuprous oxid is com- 
pletely reduced to metallic copper, cool in the current of hydrogen, and weigh. 
If preferred, a Gooch crucible may be used for the filtration. 

Herzfeld Gravimetric Method. — Tentative. 

Method I. 

(For materials containing 1.5% or less of invert sugar and 98.5% or more of sucrose.) 

35 REAGENTS. 

The reagents and solutions used are described under 24. 

36 DETERMINATION. 

Prepare the solution of the material to be examined so as to contain 20 grams in 
100 cc, free from suspended impurities by filtration and from soluble impurities by 
neutral lead acetate, removing the excess of lead by means of sodium carbonate. 
Place 50 cc. of the reagent and 50 cc. of the sugar solution in a 250 cc. beaker. Heat 
this mixture at such a rate that approximately 4 minutes are required to bring it 
to the boiling point, and boil for exactly 2 minutes. Add 100 cc. of cold, rcr-ently 
boiled, water. Filter immediately through asl)ostos, and determine the copper 
by one of the met' ods under 23, 29-34, respectively. Obtain the corresponding 
percentage of invert sugar from 37. 



VIII] 



FOODS AND FEEDING STUFFS 



99 



37 



Table 2.— Herzfeld's Table.* 



For the determination of invert sugar in materials containing 1.6%, or less, of invert 
sugar and 98.5%, or more, of sucrose. 



COPPER 




C PPER 




COPPER 




REDUCED BY 




REDUCED BY 




REDUCED BY 




10 ORAM3 


INVERT SUGAR 


10 GRAMS 


INVERT SUGAR 


10 CRAMS 


INVERT SUGAR 


OF MATERIAL 




OF MATERIAL 




OF MATERIAL 




mg. 


per cent 


mg. 


per cent 


mg. 


per cent 


50 


0.05 


140 


0.51 


230 


1.02 


55 


0.07 


145 


0.53 


235 


1.05 


60 


0.09 


150 


0.56 


240 


1.07 


65 


0.11 


155 


0.59 


245 


1.10 


70 


0.14 


160 


0.62 


250 


1.13 


75 


0.16 


165 


0.65 


255 


1.16 


80 


0.19 


170 


0.68 


260 


1.18 


85 


0.21 


175 


0.71 


265 


1.21 


90 


0.24 


180 


0.74 


270 


1.24 


95 


0.27 


185 


0.76 


275 


1.27 


100 


0.30 


190 


0.79 


280 


1.30 


105 


0.32 


195 


0.82 


285 


1.33 


110 


0.35 


200 


0.85 


290 


1.36 


115 


0.38 


205 


0.88 


295 


1.38 


120 


0.40 


210 


0.90 


300 


1.41 


125 


0.43 


215 


0.93 


305 


1.44 


130 


0.45 


220 


0.96 


310 


1.47 


135 


0.48 


225 


0.99 


315 


1.50 



Method II. 
(For materials containing 1.5% or more of invert sugar and 98.5% or less of sucrose.) 

38 



REAGENTS. 



Same as described under 24. 



DETERMINATION. 



39 

Prepare a solution of the material to be examined in such a manner that it con- 
tains 20 grams in 100 cc. after clarification and removal of the excess of lead. Pre- 
pare a series of solutions in large test tubes by adding 1, 2, 3, 4, and 5 cc. of this 
solution to each tube successively. Add 5 cc. of the reagent to each, heat to boiling, 
boil 2 minutes, and filter. Note the volume of suiiar solution which gives the fil- 
trate I'ghtest in tint, but still distinctly blue. Place 20 times this vo ume of the 
sugar solution in a 100 cc. flask, dilute to the mark, and mix well. Use .50 cc. of the 
solution for the determination, which is conducted as described under 33. For the 
calculation of the result use the following formulas and table of factors of Meissl 
and Hiller: 

Let Cu = the weight of copper obtained; 
P = the polarization of the sample; 
W = the weight of the sample in the 50 cc. of the solution used for the 

determination; 
F = the factor obtained from the table for the conversion of copper to 
invert sugar; 

Cu . . , . . 

Then — =Z, approximate weight of invert sugar; 

Z X — =Y, approximate per cent of invert sugar; 
W 



100 



METHODS OF ANALYSIS 



[Chap. 



100 P 



= R, approximate per cent of sucrose in mixture of sugars; 



P+ Y 

100 — R = I, approximate per cent of invert sugar; 

CuF 

= per cent of invert sugar. 

W 

The factor F for calculating copper to invert sugar is then found from 40. 

40 Table 3. 

Meissl and Hiller's^ factors for determinations in materials in which, of the total 
sugars present, 1.5%, or more, is invert sugar, and 9S.5%, or less, is sclerose. 







APPROXIMATE ABSOLUTE 'WEIGHT 


OF INVERT SUGAR (Z) 




RATIO or SUCROSE 
















TO INVERT 
















SUGAR = r: I. 


200 


175 


150 


125 


100 


75 


50 




milligrams 


milligrams 


milligrams 


milligrams 


milligrams 


milligrams 


milligrams 




per cent 


per cent 


per cent 


per cent 


per cent 


per cent 


per cent 


0:100 


56.4 


55.4 


54.5 


53.8 


53.2 


53.0 


53.0 


10:90 


56.3 


55.3 


54.4 


53.8 


53.2 


52.9 


52.9 


20:80 


56.2 


55.2 


54.3 


53.7 


53.2 


52.7 


52.7 


30:70 


56.1 


55.1 


54.2 


53.7 


53.2 


52.6 


52.6 


40:60 


55.9 


55.0 


54.1 


53.6 


53.1 


52.5 


52.4 


50:50 


55.7 


54.9 


54.0 


53.5 


53.1 


52.3 


52.2 


60:40 


55.6 


54.7 


53.8 


53.2 


52.8 


52.1 


51.9 


70:30 


55.5 


54.5 


53.5 


52.9 


52.5 


51.9 


51.6 


80:20 


55.4 


54.3 


53.3 


52.7 


52.2 


51.7 


51.3 


90: 10 


54.6 


53.6 


53.1 


52.6 


52.1 


51.6 


51.2 


91:9 


54.1 


53.6 


62.6 


52.1 


51.6 


51.2 


50.7 


92:8 


53.6 


53.1 


52.1 


51.6 


51.2 


50.7 


50.3 


93:7 


53.6 


53.1 


52.1 


51.2 


50.7 


50.3 


49.8 


94:6 


53.1 


52.6 


51.6 


50.7 


50.3 


49.8 


48.9 


95:5 


52.6 


52.1 


51.2 


50.3 


49.4 


48.9 


48.5 


96:4 


52.1 


51.2 


50.7 


49.8 


48.9 


47.7 


46.9 


97:3 


50.7 


50.3 


49.8 


48.9 


47.7 


46.2 


45.1 


98:2 


49.9 


48.9 


48.5 


47.3 


45.8 


43.3 


40.0 


99:1 


47.7 


47.3 


46.5 


45.1 


43.3 


41.2 


38.1 



Example: The polarization of a sugar is 86.4, and 50 cc. of solution containing 
3.256 grams of sample gave 0.290 gram of copper. 

Cu _ 0.290 
~2" ~ " 



= 0.145 = Z 



Z X 100 



= 0.145 X 



100 



4.45 



W "3.256 

100-R = 100-95.1 = I = 4.9 
R:I = 95.1:4.9 

By consulting the table it will be seen that the vertical column headed 150 is 
nearest to Z, 145, and the horizontal column headed 95: 5 is nearest to the ratio of 
R to I, 95.1 : 4.9. Where these columns meet, we find the factor 51.2 which enters 
into the final calculation: 



CuF 
W 



0.2 90 X 5 1.2 
3.256 



= 4.56 per cent of invert sugar. 



In case there is no sucrose present, the following table may be used instead of the 
factors given in 40. 



vni] 

41 



foods and feeding stuffs 

Table 4.— Meissl's Table.'' 
For the determination of invert sugar alone. 
[According to Wein.] 

[Expressed in milligrams.) 



101 



COPPER 


INVERT 
SUGAR 


COPPER 


INVERT 
SUGAR 


COPPER 


INVERT 
SUGAR 


COPPER 


INVERT 
SUGAR 


90 


46.9 


135 


70.8 


180 


95.2 


225 


120.4 


91 


47.4 


136 


71.3 


181 


95.7 


226 


120.9 


92 


47.9 


137 


71.9 


182 


96.2 


227 


121.5 


93 


48.4 


138 


72.4 


183 


96.8 


228 


122.1 


94 


48.9 


139 


72.9 


184 


97.3 


229 


122.6 


95 


49.5 


140 


73.5 


185 


97.8 


230 


123.2 


96 


50.0 


141 


74.0 


186 


98.4 


231 


123.8 


97 


50.5 


142 


74.5 


187 


99.0 


232 


124.3 


98 


51.1 


143 


75.1 


188 


99.5 


233 


124.9 


99 


51.6 


144 


75.6 


189 


100.1 


234 


125.5 


100 


52.1 


145 


76.1 


190 


100.6 


235 


126.0 


101 


52.7 


146 


76.7 


191 


101.2 


236 


126.6 


102 


53.2 


147 


77.2 


192 


101.7 


237 


127.2 


103 


53.7 


148 


77.8 


193 


102.3 


238 


127.8 


104 


54.3 


149 


78.3 


194 


102.9 


239 


128.3 


105 


54.8 


150 


78.9 


195 


103.4 


240 


128.9 


106 


55.3 


151 


79.4 


196 


104.0 


241 


129.5 


107 


55.9 


152 


80.0 


197 


104.6 


242 


130.0 


108 


56.4 


153 


80.5 


198 


105.1 


243 


130.6 


109 


56.9 


154 


81.0 


199 


105.7 


244 


131.2 


110 


57.5 


155 


81.6 


200 


106.3 


245 


131.8 


111 


58.0 


156 


82.1 


201 


106.8 


246 


132.3 


112 


58.5 


157 


82:7 


202 


107.4 


247 


132.9 


113 


59.1 


158 


83.2 


203 


107.9 


248 


133.5 


114 


59.6 


159 


83.8 


204 


108.5 


249 


134.1 


115 


60.1 


160 


84.3 


205 


109.1 


250 


134.6 


116 


60.7 


161 


84.8 


206 


109.6 


251 


135.2 


117 


61.2 


162 


85.4 


207 


110.2 


252 


135.8 


118 


61.7 


163 


85.9 


208 


110.8 


253 


136.3 


119 


62.3 


164 


86.5 


209 


111.3 


254 


136.9 


120 


62.8 


165 


87.0 


210 


111.9 


255 


137.5 


121 


63.3 


166 


87.6 


211 


112.5 


256 


138,1 


122 


63.9 


167 


88.1 


212 


113.0 


257 


138.6 


123 


64.4 


168 


88.6 


213 


113.6 


258 


139.2 


124 


64.9 


169 


89.2 


214 


114.2 


259 


139.8 


125 


65.5 


170 


89.7 


215 


114.7 


260 


140.4 


126 


66.0 


171 


90.3 


216 


115.3 


261 


140.9 


127 


66.5 


172 


90.8 


217 


115.8 


262 


141.5 


128 


67.1 


173 


91.4 


218 


116.4 


263 


142.1 


129 


67.6 


174 


91.9 


219 


117.0 


264 


142.7 


130 


68.1 


175 


92.4 


220 


117.5 


265 


143.2 


131 


68.7 


176 


93.0 


221 


llS.l 


266 


143.8 


132 


69.2 


177 


93.5 


222 


118.7 


267 


144.4 


133 


69.7 


178 


94.1 


223 


119.2 


268 


144.9 


134 


70.3 


179 


94.6 


224 


119.8 


269 


145.5 



102 
41 



METHODS OF ANALYSIS 

Table 4.— Meissl-s Table.— Continued. 

(Expressed in milligrams.] 



[Chap. 



COPPER 


INVERT 
SUGAR 


COPPER 


INVERT 
SUGAR 


COPPER 


INVERT 
SUGAR 


COPPER 


INVERT 
Sl'GAR 


270 


146.1 


310 


169.7 


350 


193.8 


390 


218.7 


271 


146.7 


311 


170.3 


351 


194.4 


391 


219.3 


272 


147.2 


312 


170.9 


352 


195.0 


392 


219.9 


273 


147.8 


313 


171.5 


353 


195.6 


393 


220.5 


274 


148.4 


314 


172.1 


354 


196.2 


394 


221.2 


275 


149.0 


315 


172.7 


355 


196.8 


395 


221.8 


276 


149.5 


316 


173.3 


356 


197.4 


396 


222.4 


277 


150.1 


317 


173.9 


357 


198.0 


397 


223.1 


278 


150.7 


318 


174.5 


358 


198.6 


398 


223.7 


279 


151.3 


319 


175.1 


359 


199.2 


399 


224.3 


280 


151.9 


320 


175.6 


360 


199.8 


400 


224.9 


281 


152.5 


321 


176.2 


361 


200.4 


401 


225.7 


282 


153.1 


322 


176.8 


362 


201.1 


402 


226.4 


283 


153.7 


323 


177.4 


363 


201.7 


403 


227.1 


284 


154.3 


324 


178.0 


364 


202.3 


404 


227.8 


285 


154.9 


325 


178.6 


365 


203.0 


405 


228.6 


286 


155.5 


326 


179.2 


366 


203.6 


406 


229.3 


287 


156 . 1 


327 


179.8 


367 


204.2 


407 


230.0 


288 


156.7 


328 


180.4 


368 


204.8 


408 


230.7 


289 


157.2 


329 


181.0 


369 


205.5 


409 


231.4 


290 


157.8 


330 


181.6 


370 


206.1 


410 


232.1 


291 


158.4 


331 


182.2 


371 


206.7 


411 


232.8 


292 


159.0 


332 


182.8 


372 


207.3 


412 


233.5 


293 


159.6 


333 


183.5 


373 


208.0 


413 


234.3 


294 


160.2 


334 


184.1 


374 


208.6 


414 


235.0 


295 


160.8 


335 


184.7 


375 


209.2 


415 


235.7 


296 


161.4 


336 


185.4 


376 


209.9 


416 


236.4 


297 


162.0 


337 


186.0 


377 


210.5 


417 


237.1 


298 


162.6 


338 


l.«6.6 


378 


211.1 


418 


237.8 


299 


163.2 


339 


187.2 


379 


211.7 


419 


238.5 


300 


163.8 


340 


187.8 


380 


212.4 


420 


239.2 


301 


16t.4 


341 


188.4 


381 


213.0 


421 


2.39.9 


302 


165.0 


342 


189.0 


382 


213.6 


422 


240.6 


303 


165.6 


343 


189.6 


383 


214.3 


423 


241.3 


304 


166.2 


344 


190.2 


384 


214.9 


424 


242.0 


305 


166.8 


345 


190.8 


385 


215.5 


425 


242.7 


306 


167.3 


316 


191.4 


386 


216.1 


426 


243.4 


307 


167.9 


317 


192.0 


387 


216.8 


427 


244.1 


308 


168. 5 


348 


192.6 


388 


217.4 


428 


244.9 


309 


169.1 


349 


193.2 


389 


218.0 


429 
430 


245.6 
246.3 



MALTOSE. 

42 General Gravimetric Method. — Tentative. 

Proceed as directed under 25 and obtain, from 27. the weight of maltose 
equivalent to the weight of copper reduced. 



VIII] 



FOODS AND FEEDING STUFFS 



103 



Wein Method. — Tentative. 

43 REAGENTS. 

The reagents and solutions used are described under 24. 

44 DETERMINATION. 

Place 50 cc. of the reagent in a beaker and heat to the boiling point. When 
boiling briskly, add 25 cc. of the maltose solution containing not more than 0.250 
gram of maltose and boil for 4 minutes. Filter immediately through asbestos and 
determine, by one of the methods given under 26, 29-34 respectively, the amount of 
copper reduced. 
Obtain, from 45, the weight of maltose equivalent to the weight of copper found. 



45 



Table 5. 

For the determination of maltose. 

[According to Wein.'] 

[Expressed in milligrams.] 



COPPBR 


ca- 

PROTJ8 
OXID 


MAL- 
TOSE! 


COPPER 


CU- 
PROUS 
OXID 


MAL- 
TOSE 


COPPER 


CU- 
PROUS 
OXID 


MAL- 
TOSE 


COPPER 


CU- 
PROUS 
OXID 


MAL- 
TOSE 


31 


34.9 


26.1 


71 


79.9 


61.0 


111 


125.0 


96.4 


151 


170,0 


132.3 


32 


36.0 


27.0 


72 


81.1 


61.8 


112 


126.1 


97,3 


152 


171,1 


133.2 


33 


37.2 


27.9 


73 


82.2 


62.7 


113 


127.2 


98.1 


153 


172,3 


134 1 


34 


38.3 


28.7 


74 


83.3 


63.6 


114 


128.3 


99.0 


154 


173.4 


135.0 


35 


39.4 


29.6 


75 


84.4 


64.5 


115 


129.6 


99.9 


155 


174.6 


135.9 


36 


40.5 


30.5 


76 


85.6 


65.4 


116 


130.6 


100,8 


156 


175.6 


136.8 


37 


41.7 


31.3 


77 


86.7 


66.2 


117 


131.7 


101 7 


157 


176.8 


1.37.7 


38 


42.8 


32.2 


78 


87.8 


67.1 


118 


132.8 


102.6 


158 


177.9 


138.6 


39 


43.9 


33.1 


79 


88.9 


68.0 


119 


134.0 


103.5 


159 


179 


139,5 


40 


45.0 


33.9 


80 


90.1 


68.9 


120 


135.1 


104.4 


160 


180.1 


140.4 


41 


46.2 


34.8 


81 


91.2 


69 7 


121 


136,2 


105.3 


161 


181.3 


141.3 


42 


47.3 


35.7 


82 


92.3 


70.6 


122 


137,4 


106.2 


162 


182,4 


142,2 


43 


48.4 


36.5 


83 


93.4 


71.6 


123 


138,5 


107.1 


163 


183,5 


143.1 


44 


49.5 


37.4 


84 


94.6 


72.4 


124 


139,6 


108.0 


164 


184,6 


144.0 


45 


60.7 


38.3 


85 


95.7 


73.2 


125 


140.7 


108.9 


165 


185.8 


144.9 


46 


61.8 


39.1 


86 


96.8 


74.1 


126 


141.9 


109,8 


166 


186.9 


145.8 


47 


52.9 


40.0 


87 


97.9 


75.0 


127 


143,0 


110,7 


167 


188.0 


146.7 


48 


54,0 


40.9 


88 


99.1 


75.9 


128 


144,1 


111.6 


168 


189,1 


147.6 


49 


55.2 


41.8 


89 


100.2 


76.8 


129 


145.2 


112.5 


169 


190,3 


148.5 


60 


56.3 


42.6 


90 


101.3 


77.7 


130 


146.4 


113.4 


170 


191.4 


149.4 


51 


57.4 


43.5 


91 


102 4 


78.6 


131 


147,5 


114,3 


171 


192.5 


150,3 


52 


58.5 


44.4 


92 


103.6 


79.5 


132 


148 6 


115 2 


172 


193.6 


151.2 


63 


69.7 


45.2 


93 


104.7 


80.3 


133 


149,7 


116.1 


173 


194.8 


152.0 


54 


60.8 


46.1 


94 


105.8 


81.2 


134 


150 9 


117.0 


174 


195.9 


152.9 


65 


61.9 


47.0 


95 


107.0 


82.1 


135 


152.0 


117.9 


175 


197.0 


153.8 


56 


63.0 


47.8 


96 


108.1 


83.0 


136 


1.53.1 


118.8 


176 


198.1 


154.7 


57 


64.2 


48.7 


97 


109.2 


83.9 


137 


154.2 


119.7 


177 


109.3 


155.6 


58 


65.3 


49.6 


98 


110.3 


84.8 


138 


155,4 


120,6 


178 


200,4 


156,5 


59 


66 4 


50.4 


99 


111.5 


85.7 


139 


156.5 


121,5 


179 


201,5 


157.4 


60 


67.6 


61.3 


100 


112.6 


86.6 


140 


157.6 


122.4 


180 


202.6 


158.3 


61 


68.7 


52.2 


101 


113.7 


87.5 


141 


158.7 


123.3 


181 


203,8 


159.2 


62 


69.8 


63.1 


102 


114.8 


88.4 


142 


159.9 


124.2 


182 


204.9 


160.1 


63 


70.9 


53.9 


103 


116.0 


89.2 


143 


161. 


125.1 


183 


206 


160,9 


64 


72.1 


54.8 


104 


117.1 


90.1 


144 


162,1 


126.0 


184 


207.1 


161.8 


65 


73.2 


55.7 


105 


118.2 


91.0 


145 


163.2 


126.9 


185 


208.3 


162.7 


66 


74.3 


56.6 


106 


119.3 


91.9 


146 


164.4 


127.8 


186 


209.4 


163.6 


67 


75.4 


57.4 


107 


120.5 


92.8 


147 


165.5 


128.7 


187 


210 5 


164.6 


68 


76.6 


58.3 


108 


121.6 


93.7 


148 


166.6 


129,6 


188 


211 7 


165 4 


69 


77.7 


59.2 


109 


122.7 


94 6 


149 


167.7 


130 5 


189 


212 8 


166.3 


70 


78.8 


60.1 


110 


123.8 


95.5 


150 


168.9 


131.4 


190 


213.9 


167.2 



104 
45 



46 



METHODS OF ANALYSIS 

Table 5.— Continued. 

For the determination of maltose. 

[Expressed in milligrams.) 



[Chap. 



COPPER 


co- 

PUOU8 
OXID 


MAL- 
TO.SB 


COPPER 


CU- 
PROUS 
OXID 


MAL- 
TOSE 


COPPER 


CU- 
PROUS 
OXID 


MAL- 
TOSE 


COPPER 


CU- 
PROUS 
OXID 


MAL- 
T08B 


191 


215.0 


168.1 


221 


248.7 


194.8 


251 


282.6 


221.7 


281 


316.4 


248.7 


192 


216.2 


169.0 


222 


249.9 


195.7 


252 


283 7 


222,6 


282 


317,5 


249.0 


193 


217.3 


169.8 


223 


251.0 


196.6 


253 


284.8 


223.5 


283 


318,6 


250.4 


194 


218.4 


170.7 


224 


252.4 


197.5 


254 


286.0 


224.4 


284 


319,7 


251.3 


195 


219.5 


171 6 


225 


253.3 


198.4 


255 


287.1 


225.3 


285 


320 9 


252.2 


196 


220.7 


172.5 


226 


254.4 


199.3 


256 


288.2 


226.2 


286 


322.0 


253.1 


197 


221.8 


173.4 


227 


255.6 


200.2 


257 


2.S9.3 


227 1 


287 


323.1 


2.54.0 


198 


222.9 


174.3 


228 


2.56.7 


201.1 


258 


290.5 


228 


288 


324.2 


2.54.9 


199 


224,0 


175.2 


229 


257.8 


202 


259 


291 6 


228.9 


289 


325.4 


2.55.8 


200 


225.2 


176.1 


230 


258.9 


202.9 


260 


292.7 


229.8 


290 


326.5 


256.6 


201 


226.3 


177.0 


231 


260.1 


203.8 


261 


293.8 


230.7 


291 


327.4 


257.6 


202 


227.4 


177.9 


232 


261 2 


204.7 


262 


295.0 


231,6 


292 


328.7 


2.58.4 


20.3 


228.5 


178.7 


233 


262.3 


205.6 


263 


296.1 


232,5 


293 


329.9 


259.3 


204 


229.7 


179.6 


234 


263.4 


206.5 


264 


297.2 


233,4 


294 


331.0 


260.2 


205 


230.8 


180.5 


235 


264.6 


207.4 


265 


298.3 


234.3 


295 


332.1 


261.1 


206 


231.9 


181.4 


236 


265.7 


208.3 


266 


299 5 


235,2 


296 


333.2 


262.0 


207 


233.0 


182.3 


237 


206,8 


209 1 


267 


300.6 


236,1 


297 


3.34.4 


262.8 


208 


234.2 


183.2 


238 


208.0 


210 


268 


301.7 


237 


298 


335.5 


263.7 


209 


2.35.3 


184.1 


239 


269.1 


210.9 


269 


302 8 


237,9 


299 


336.6 


264,6 


210 


236.4 


185.0 


240 


270.2 


211.8 


270 


304.0 


238.8 


300 


337.8 


265,5 


211 


237.6 


185.9 


241 


271.3 


212.7 


271 


305.1 


239 7 








212 


238.7 


186.8 


242 


272.5 


213.6 


272 


306.2 


240.6 








213 


239.8 


187.7 


243 


273,6 


214.5 


273 


307.3 


241.5 








214 


240.9 


188.6 


244 


274.7 


215.4 


274 


308. 5 


242.4 








215 


242.1 


189.5 


245 


275.8 


216.3 


275 


309.6 


243.3 








216 


243.2 


190.4 


246 


277.0 


217.2 


276 


310,7 


244 2 








217 


244.3 


191.2 


247 


278.1 


218 1 


277 


311.9 


245,1 








218 


245.4 


192.1 


248 


279.2 


219.0 


278 


313 


246,0 








219 


246.6 


193.0 


249 


280.3 


219.9 


279 


314,1 


246,9 








220 


247.7 


193.9 


250 


281.5 


220.8 


280 


315,2 


247.8 









LACTOSE. 

General Gravimetric Method. — Tentative. 



Proceed as directed under 25 and obtain, from 27, the weight of lactose 
equivalent to the weight of copper reduced. 

Soxhlet-Wein Method. — Official. 

47 REAGENTS. 

The reagents and sohitions used are described under 24. 



48 



DETERMINATION. 



Place 50 cc. of the reagent in a beaker and heat to the boiling point. When 
boiling briskly, add 100 cc. of the lactose solution containing not more than 0.300 
gram of lactose and boil for G minutes. Filter immediately through asbestos and 
determine by one of the methods given under 26, 29-34 inclusive, the amount of 
copper reduced. Obtain, from 49, the weight of lactose equivalent to the weight of 
copper found. 



VIII] 
49 



FOODS AND FEEDING STUFFS 

TABLE 6. 

For the determination of lactose (Soxhlet-Wein^). 

[Expressed in milligrams.) 



105 



COPPER 


LACTOSE 


COPPER 


LACTOSE 


COPPER 


LACTOSE 


COPPER 


LACTOSE 


COPPER 


LACTOSE 


100 


71.6 


160 


116.4 


220 


161.9 


280 


208.3 


340 


255.7 


101 


72.4 


161 


117.1 


221 


162.7 


281 


209.1 


341 


256.5 


102 


73.1 


162 


117.9 


222 


163.4 


282 


209.9 


342 


2.57.4 


103 


73.8 


163 


118.6 


223 


164.2 


283 


210.7 


343 


2.58.2 


104 


74.6 


164 


119.4 


224 


164.9 


284 


211.5 


344 


259.0 


105 


75.3 


165 


120.2 


225 


165.7 


285 


212.3 


345 


259.8 


106 


76.1 


166 


120.9 


226 


166.4 


286 


213.1 


346 


260.6 


107 


76.8 


167 


121.7 


227 


167.2 


287 


213.9 


347 


261.4 


108 


77.6 


108 


122 4 


228 


167.9 


288 


214.7 


348 


262.3 


109 


78.3 


169 


123.2 


229 


168.6 


289 


215.5 


349 


263.1 


110 


79 


170 


123.9 


230 


169.4 


200 


216.3 


3.50 


263.9 


111 


79.8 


171 


124.7 


231 


170.1 


291 


217.1 


351 


264.7 


112 


80.5 


172 


125.5 


232 


170.9 


292 


217.9 


352 


265.5 


113 


81.3 


173 


126.2 


233 


171.6 


293 


218.7 


353 


266.3 


114 


82.0 


174 


127.0 


234 


172.4 


294 


219.5 


354 


267.2 


115 


82.7 


175 


127.8 


235 


173.1 


295 


220.3 


3.55 


• 268.0 


116 


83 5 


176 


128.5 


236 


173.9 


296 


221.1 


356 


268.8 


117 


84.2 


177 


129.3 


237 


174.6 


297 


221.9 


3,57 


269.6 


118 


85.0 


178 


130.1 


238 


175 4 


298 


222.7 


358 


270.4 


119 


85.7 


179 


130.8 


239 


176.2 


299 


223.5 


359 


271.2 


120 


86.4 


180 


131.6 


240 


176.9 


300 


224.4 


360 


272.1 


121 


87.2 


181 


132.4 


241 


177.7 


.301 


225.2 


301 


272.9 


122 


87.9 


182 


133.1 


242 


178.5 


302 


225.9 


362 


273.7 


123 


88.7 


183 


133.9 


243 


179.3 


303 


226.7 


363 


274.5 


124 


89.4 


184 


134.7 


244 


180.1 


304 


227.5 


304 


275.3 


125 


90.1 


185 


135.4 


245 


180.8 


305 


228.3 


365 


276.2 


126 


90.9 


186 


136.2 


246 


181.6 


306 


229.1 


366 


277.1 


127 


91.6 


187 


137.0 


247 


182.4 


307 


229 8 


367 


277.9 


128 


92.4 


188 


137.7 


248 


183.2 


308 


230.6 


368 


278.8 


129 


93.1 


189 


138.5 


249 


184.0 


309 


231.4 


309 


279.6 


130 


93.8 


190 


139.3 


250 


184.8 


310 


2.32.2 


370 


280.5 


131 


94.6 


191 


140 


251 


185.5 


311 


232 9 


371 


281.4 


132 


95.3 


192 


140.8 


252 


186.3 


312 


2.i3.7 


372 


282.2 


133 


96.1 


193 


141.6 


253 


187.1 


313 


2,34.5 


373 


283.1 


134 


90.9 


194 


142.3 


254 


187.9 


314 


235.3 


374 


283.9 


135 


97.6 


195 


143.1 


255 


188.7 


315 


230.1 


375 


284.8 


136 


98.3 


196 


143.9 


256 


189.4 


316 


236,8 


376 


285.7 


137 


99.1 


197 


144.6 


257 


190.2 


317 


237.6 


377 


286.5 


138 


99.8 


198 


145.4 


258 


191.0 


318 


238.4 


378 


287.4 


139 


100.5 


199 


140.2 


259 


191.8 


319 


239.2 


379 


288.2 


140 


101.3 


200 


146.9 


260 


192.5 


320 


240.0 


380 


289.1 


141 


102.0 


201 


147.7 


201 


193.3 


321 


240.7 


381 


289.9 


142 


102.8 


202 


148.5 


262 


194.1 


322 


241.5 


382 


290.8 


143 


103.5 


203 


149.2 


203 


194.9 


323 


242.3 


383 


291.7 


144 


104.3 


201 


150.0 


264 


195.7 


324 


243.1 


384 


292.5 


145 


105.1 


205 


1.50.7 


265 


196.4 


325 


243.9 


385 


293.4 


146 


105.8 


206 


151.5 


266 


197 2 


326 


244.6 


386 


294.2 


147 


108.6 


207 


1.52.2 


267 


198.0 


327 


245.4 


387 


295.1 


148 


107.3 


208 


1.53,0 


208 


198.8 


328 


246.2 


388 


290.0 


149 


108.1 


209 


153.7 


269 


199.5 


329 


247.0 


389 


296.8 


150 


108.8 


210 


1.54.5 


270 


200.3 


3.30 


247.7 


390 


297.7 


151 


109.6 


211 


1.55.2 


271 


201.1 


331 


248.5 


391 


298.5 


152 


110.3 


212 


1.56.0 


272 


201.9 


332 


249.2 


392 


299.4 


153 


111.1 


213 


1.56.7 


273 


202.7 


333 


2.50.0 


393 


300.3 


154 


111.9 


214 


1.57.5 


274 


203.5 


334 


2,50.8 


394 


301.1 


155 


112.6 


215 


1.58.2 


275 


204.3 


335 


251.6 


395 


302.0 


156 


113.4 


216 


1.50 


276 


205.1 


336 


252 5 


396 


302.8 


157 


114.1 


217 


1.59.7 


277 


205.9 


' 337 


2.53.3 


397 


303 7 


158 


114.9 


218 


160.4 


278 


206.7 


338 


254.1 


398 


304.6 


159 


115.6 


219 


161.2 


279 


207.5 


339 


254.9 


399 
400 


305.4 
306.3 



106 METHODS OP ANALYSIS [Chap. 

DEXTROSE. 

50 Approximate Volumetric Method for Rapid Work. — Tentative. 
Proceed as directed under 21 . Standardize the reagent against pure dextrose. 

51 Soxhlet Method. — Tentative. 

Proceed as directed under 23. Under these conditions 100 cc. of the reagent 

require 0.475 gram of anhydrous dextrose for complete reduction and the formula 

, 100 X 0.475 ^ , , ^ 

becomes = per cent of dextrose. 

VW 

52 General Gravimetric Method. — Tentative. 

Proceed as directed under 25 and obtain, from 27, the weight of dextrose equiv- 
alent to the weight of copper reduced. 

Allihn Gravimetric Method. — Tentative. 

53 REAGENT. 

Allihn's Modification of Fehling's Solution. — Prepare by mixing, immediately 
before use, equal volumes of (a) and (b). 

(a) Copper sulphate solution. — Dissolve 34.639 grams of copper sulphate 
(CuS045H,iO) in water and dilute to 500 cc. 

(b) Alkaline tartrate solution. — Dissolve 173 grams of Rochelle salts and 125 
grams of potassium hydroxid in water and dilute to 500 cc. 

54 DETERMINATION. 

Place 30 cc. of the copper sulphate solution, 30 cc. of the alkaline tartrate solu- 
tion, and 60 cc. of water in a beaker and heat to boiling. Add 25 cc. of the solution 
of the material to be examined, prepared so as not to contain more than 0.25 gram 
of dextrose, and boil for exactly 2 minutes, keeping the beaker covered. Filter 
immediately through asbestos, and obtain the weight of copper by one of the methods 
given under 26, 29-34 inclusive. The corresponding weight of dextrose is found 
in 55. 



VIII] 
55 



foods and feeding stuffs 

Table 7.— Allihn's Table. i<» 

For the determination of dextrose. 

[Expressed in milligrams.) 



107 



COPPER 


CU- 
PROUS 
OXID 


DEX- 
TROSE 


COPPER 


CU- 
PROUS 

o.aD 


DEX- 
TROSE 


COPPER 


CU- 
PROUS 
OXID 


DEX- 
TROSE 


COPPER 


CU- 
PROUS 
OXID 


DBX- 
TROSB 


11 


12.4 


6.6 


71 


79.9 


36.3 


131 


147.5 


66.7 


191 


215.0 


97.8 


12 


13.5 


7.1 


72 


81.1 


36.8 


132 


148.6 


67.2 


192 


216.2 


98.4 


13 


14.6 


7.6 


73 


82.2 


37.3 


133 


149.7 


67.7 


193 


217.3 


98.9 


14 


15.8 


8.1 


74 


83.3 


37.8 


134 


150.9 


68.2 


194 


218.4 


99.4 


15 


16.9 


8.6 


75 


84.4 


38.3 


135 


152.0 


68.8 


195 


219.5 


100.0 


16 


18.0 


9.0 


76 


85.6 


38.8 


136 


153.1 


69.3 


196 


220.7 


100.5 


17 


19.1 


9.5 


77 


86.7 


39 3 


137 


154.2 


69.8 


197 


221 8 


101.0 


18 


20.3 


10.0 


78 


87.8 


39.8 


138 


155.4 


70.3 


198 


222.9 


101.5 


19 


21.4 


10.5 


79 


88.9 


40.3 


139 


156.5 


70 8 


199 


224.0 


102.0 


20 


22.5 


11.0 


80 


90.1 


40.8 


140 


157.6 


71.3 


200 


225.2 


102.8 


21 


23 6 


11.5 


81 


91.2 


41.3 


141 


158.7 


71.8 


201 


226.3 


103.1 


22 


24.8 


12.0 


82 


92.3 


41.8 


142 


159.9 


72 3 


202 


227.4 


103.7 


23 


25.9 


12.5 


83 


93.4 


42.3 


143 


161.0 


72.9 


203 


228.5 


104.2 


24 


27.0 


13.0 


84 


94.6 


42.8 


144 


162.1 


73.4 


204 


229.7 


104.7 


25 


28.1 


13.5 


85 


95.7 


43.4 


145 


163.2 


73.9 


205 


230.8 


105.3 


26 


29.3 


14.0 


86 


96.8 


43.9 


146 


164.4 


74.4 


206 


231.9 


105.8 


27 


30.4 


14.5 


87 


97.9 


44.4 


147 


165.5 


74.9 


207 


233.0 


106.3 


28 


31.5 


15.0 


88 


99.1 


44.9 


148 


166.6 


75.5 


208 


234.2 


106.8 


29 


32.7 


15.5 


89 


100.2 


45.4 


149 


167.7 


76.0 


209 


235.3 


107.4 


30 


33.8 


16.0 


90 


101 3 


45.9 


150 


168.9 


76.5 


210 


236.4 


107.9 


31 


34.9 


16.5 


91 


102.4 


46.4 


151 


170.0 


77.0 


211 


237.6 


108.4 


32 


36.0 


17.0 


92 


103.6 


46.9 


152 


171.1 


77.5 


212 


238.7 


109.0 


3S 


37.2 


17.5 


93 


104.7 


47.4 


153 


172.3 


78.1 


213 


239.8 


109.5 


34 


38.3 


18.0 


94 


105.8 


47.9 


154 


173.4 


78.6 


214 


240.9 


110 


35 


39.4 


18.5 


95 


107.0 


48.4 


155 


174.5 


79.1 


215 


242.1 


110.6 


36 


40 5 


18.9 


96 


108.1 


48.9 


156 


175.6 


79.6 


216 


243.2 


111.1 


37 


41.7 


19.4 


97 


109.2 


49.4 


1.57 


176.8 


80.1 


217 


244.3 


111.0 


38 


42.8 


19.9 


98 


110.3 


49.9 


158 


177.9 


80.7 


218 


245.4 


112.1 


39 


43.9 


20.4 


99 


111.5 


50.4 


159 


179.0 


81.2 


219 


246.6 


112.7 


40 


45.0 


20.9 


100 


112.6 


50.9 


160 


180.1 


81.7 


220 


247.7 


113.2 


41 


46.2 


21.4 


101 


113.7 


51.4 


161 


181.3 


82.2 


221 


248.7 


113.7 


42 


47.3 


21.9 


102 


114.8 


51.9 


162 


182.4 


82.7 


222 


249.9 


114.3 


43 


48.4 


22.4 


103 


116.0 


52.4 


163 


183.5 


83.3 


223 


251.0 


114.8 


44 


49.5 


22.9 


104 


117.1 


52.9 


164 


184.6 


83.8 


224 


252.4 


115.3 


45 


50.7 


23.4 


105 


118.2 


53.5 


165 


185.8 


84.3 


225 


253.3 


115.9 


46 


51.8 


23.9 


106 


119.3 


54.0 


166 


186.9 


84.8 


226 


254.4 


116.4 


47 


52.9 


24.4 


107 


120 5 


54.5 


167 


188.0 


85.3 


227 


255.6 


116.9 


48 


54 


24.9 


108 


121.6 


55.0 


168 


189.1 


85.9 


228 


256.7 


117.4 


49 


55.2 


25.4 


109 


122.7 


55.5 


169 


190.3 


86.4 


229 


257.8 


118.0 


50 


56.3 


25.9 


110 


123.8 


56.0 


170 


191.4 


86.9 


230 


258.9 


118.5 


51 


57.4 


26.4 


111 


125.0 


56.5 


171 


192.5 


87.4 


231 


260.1 


119.0 


52 


58.5 


26.9 


112 


126.1 


57.0 


172 


193.6 


87.9 


232 


261.2 


119.6 


53 


59.7 


27.4 


113 


127.2 


57.5 


173 


194.8 


88.5 


233 


262.3 


120.1 


54 


60.8 


27.9 


114 


128.3 


58.0 


174 


195.9 


89.0 


234 


263.4 


120.7 


55 


61.9 


28.4 


115 


129.6 


58.6 


175 


197.0 


89.5 


235 


264.6 


121.2 


56 


63.0 


28.8 


116 


130.6 


59.1 


176 


198.1 


90.0 


236 


265.7 


121.7 


57 


64.2 


29.3 


117 


131.7 


59.6 


177 


199.3 


90.5 


237 


266.8 


122.3 


58 


65.3 


29.8 


118 


132.8 


60.1 


178 


200.4 


91.1 


238 


268.0 


122.8 


59 


66.4 


30.3 


119 


134.0 


60.6 


179 


201.5 


91.6 


239 


269.1 


123.4 


60 


67.6 


30.8 


120 


135.1 


61.1 


180 


202.6 


92.1 


240 


270.2 


123.9 


61 


68.7 


31.3 


121 


136.2 


61.6 


181 


203.8 


92.6 


241 


271.3 


124.4 


62 


69.8 


31.8 


122 


137.4 


62.1 


182 


204.9 


93.1 


242 


272.5 


125.0 


63 


70.9 


32.3 


123 


138.5 


62.6 


183 


206.0 


93.7 


243 


273.6 


125.5 


64 


72.1 


32.8 


124 


139.6 


63 1 


184 


207.1 


94.2 


244 


274.7 


126.0 


65 


73.2 


33.3 


125 


140.7 


63.7 


185 


208.3 


94.7 


245 


275.8 


126.6 


66 


74.3 


33.8 


126 


141 9 


64.2 


186 


209.4 


95.2 


246 


277.0 


127.1 


67 


75.4 


34.3 


127 


143.0 


64.7 


187 


210.5 


95.7 


247 


278.1 


127.6 


68 


76.6 


34.8 


128 


144 1 


65.2 


188 


211.7 


96.3 


248 


279.2 


128.1 


69 


77.7 


35.3 


129 


145.2 


65.7 


189 


212.8 


96.8 


249 


280.3 


128 7 


70 


78.8 


35.8 


130 


146.4 


66.2 


190 


213.9 


97.3 


250 


281.5 


129.2 



108 
55 



METHODS OF ANALYSIS 

Table 7.— Allihn'S Table.— Continued. 

[Expressed in milligrams.] 



[Chap. 



COPPER 


CU- 
PROUS 
OXID 


DEX- 
TROSE 


COPPER 


CU- 
PROUS 
OXID 


DEX- 
TROSE 


COPPER 


CU- 
PROUS 
OXID 


DEX- 
TROSE 


COPPER 


CU- 
PROUS 
OXID 


DEX- 
TROSE 


251 


282.6 


129,7 


306 


344,5 


159,8 


361 


406.4 


190,6 


416 


468.4 


222.2 


252 


283.7 


130,3 


307 


345,6 


160,4 


362 


407.6 


191,1 


417 


469.5 


222.8 


253 


284.8 


130.8 


308 


346,8 


160,9 


363 


408.7 


191.7 


418 


470.6 


223 3 


254 


286.0 


131.4 


309 


347,9 


161,5 


364 


409.8 


192.3 


419 


471,8 


223.9 


255 


287.1 


131.9 


310 


349,0 


162,0 


365 


410.9 


192 9 


420 


472.9 


224.5 


256 


288.2 


132.4 


311 


3,50,1 


162.6 


366 


412.1 


193.4 


421 


474.0 


225.1 


257 


289.3 


133,0 


312 


351,3 


163,1 


367 


413,2 


194.0 


422 


475 6 


225.7 


258 


290.5 


133,5 


313 


352,4 


163,7 


368 


414,3 


194.6 


423 


476,2 


226 3 


259 


291.6 


1.34,1 


314 


353,5 


164,2 


369 


415,4 


195.1 


424 


477 4 


226.9 


260 


292.7 


134,6 


315 


354.6 


164,8 


370 


416.6 


195.7 


425 


478.5 


227.5 


261 


293.8 


135,1 


316 


355,8 


165.3 


371 


417,7 


196,3 


426 


479 6 


228.0 


262 


295,0 


135,7 


317 


356,9 


105 9 


372 


418,8 


196,8 


427 


480.7 


228.6 


263 


296.1 


136,2 


318 


358,0 


166.4 


373 


420,0 


197.4 


428 


481 9 


229.2 


264 


297.2 


136,8 


319 


3.59.1 


167.0 


374 


421,1 


198.0 


429 


483.0 


229 8 


265 


298.3 


137.3 


320 


360,3 


167.5 


375 


422.2 


198.6 


430 


484.1 


230.4 


266 


299.5 


137.8 


321 


361,4 


168.1 


376 


423.3 


199.1 


431 


485.3 


231.0 


267 


300,6 


138.4 


322 


362,5 


168.6 


377 


424.5 


199.7 


432 


486 4 


231.6 


268 


301.7 


1.38.9 


323 


363,7 


169.2 


378 


425.6 


200.3 


433 


487.5 


232.2 


269 


302.8 


139.5 


324 


364,8 


169 7 


379 


426.7 


200,8 


434 


488,6 


2.32.8 


270 


304.0 


140.0 


325 


365.9 


170.3 


380 


427.8 


201,4 


435 


489,7 


233.4 


271 


305.1 


140.6 


326 


367.0 


170.3 


381 


429 


202,0 


436 


490,9 


233.9 


272 


306.2 


141.1 


327 


368.2 


171.4 


382 


430.1 


202.5 


437 


492,0 


2.34.5 


273 


307,3 


141.7 


328 


369.3 


172.0 


383 


431.2 


203.1 


438 


493,1 


235.1 


274 


308,5 


142,2 


329 


370.4 


172 5 


384 


4.32.3 


203.7 


439 


494,3 


2.35.7 


275 


309.6 


142,8 


330 


371.5 


173.1 


385 


433.5 


204.3 


440 


495.4 


236.3 


276 


310.7 


143,3 


331 


372.7 


173.7 


386 


434.6 


204.8 


441 


496.5 


236.9 


277 


311.9 


143,9 


332 


373.8 


174.2 


387 


435.7 


205.4 


442 


497.6 


237 5 


278 


313.0 


144,4 


333 


374.9 


174.8 


388 


4.36,8 


206.0 


443 


498 8 


238.1 


279 


314.1 


145,0 


334 


376.0 


175.3 


389 


4,38.0 


203 5 


444 


499 9 


2.38,7 


280 


315.2 


145.5 


335 


377.2 


175.9 


390 


439,1 


207.1 


445 


501 


239.3 


281 


316.4 


146.1 


336 


378.3 


176.5 


391 


440,2 


207.7 


446 


502.1 


2,39.8 


282 


317.5 


146.6 


337 


379.4 


177.0 


392 


441,3 


208.3 


447 


503.2 


240.4 


283 


318.6 


147.2 


338 


380.5 


177.6 


393 


442,4 


208.8 


448 


504.4 


241 


284 


319.7 


147.7 


3.39 


381.7 


178.1 


394 


443,6 


209.4 


449 


505,5 


241.6 


285 


320.9 


148.3 


340 


382.8 


178.7 


395 


444.7 


210 


450 


506 6 


242.2 


286 


322.0 


148.8 


341 


383.9 


179.3 


396 


445.9 


210.6 


451 


507,8 


242.8 


287 


323 1 


149 4 


342 


385.0 


179.8 


397 


447.0 


211.2 


452 


508,9 


243.4 


288 


324.2 


149.9 


343 


386.2 


180.4 


398 


448.1 


211 7 


453 


510,0 


244.0 


289 


325.4 


150.5 


344 


387.3 


180.9 


399 


449,2 


212,3 


454 


511,1 


244.6 


290 


326.5 


151.0 


345 


3S8.4 


181.5 


400 


450 3 


212,9 


455 


512,3 


245.2 


291 


327.4 


151.6 


346 


389.6 


182.1 


401 


451,5 


213,5 


456 


513,4 


245.7 


292 


328.7 


152.1 


347 


390.7 


182.6 


402 


452,6 


214,1 


457 


514.5 


246.3 


293 


329.9 


1.52.7 


348 


391.8 


183.2 


403 


453,7 


214,6 


458 


515 6 


246.9 


294 


331.0 


1.53,2 


349 


392.9 


183,7 


404 


454.8 


215,2 


459 


516.8 


247.5 


295 


332.1 


153,8 


350 


394.0 


184,3 


405 


456.0 


215,8 


460 


517.9 


248.1 


296 


333.3 


154,3 


351 


395.2 


184,9 


406 


457.1 


216,4 


461 


519.0 


248.7 


297 


334.4 


154,9 


352 


396.3 


185,4 


407 


458.2 


217,0 


462 


520 1 


249.3 


298 


335.5 


1.55,4 


353 


397.4 


186,0 


408 


459.4 


217.5 


463 


521.3 


249.9 


299 


336,6 


1.56,0 


354 


398,6 


186,6 


409 


460.5 


21S.1 








300 


337.8 


150,5 


355 


399,7 


187.2 


410 


461.6 


218.7 








301 


338.9 


157.1 


356 


400,8 


187.7 


411 


462.7 


219.3 








302 


340,0 


157.6 


357 


401 9 


188.3 


412 


463.8 


219 9 








303 


341,1 


1.58,2 


358 


403,1 


1.88 9 


413 


465.0 


220,4 








804 


342 3 


1.58,7 


3.59 


404,2 


189,4 


414 


466,1 


221.0 








305 


343 4 


1.59 3 


360 


405 3 


190.0 


415 


467 2 


221.6 









Vin] FOODS AND FEEDING STUFFS 109 

56 REDUCING SUGARS OTHER THAN DEXTROSE. 

Proceed as directed under 54 and multiply the weight of dextrose found in 55 
by the following factors : 

Levulose, 1.093; 
Invert sugar, 1.046; 
Arabinose, 0.969; 
Xylose, 1.017; 

Galactose, 1.114. 

Total Sugars." 
(Applicable to cattle foods.) 

57 PREPARATION OF SOLUTION. 

Place 12 grams of the material in a 300 cc. graduated flask, if the substance has an 
acid reaction add 1-3 grams of calcium carbonate, and boil on a steam bath for 1 hour 
with 150 cc. of 50% alcohol by volume, using a small funnel in the neck of the flask 
to condense the vapor. Cool, and allow the mixture to stand several hours, prefer- 
ably overnight. Make up to volume with neutral 95% alcohol, mix thoroughly, 
allow to settle, transfer 200 cc. to a beaker with a pipette, and evaporate on a steam 
bath to a volume of 20-30 cc. 

Do not evaporate to dryness, a little alcohol in the residue doing no harm. Trans- 
fer to a 100 cc. graduated flask, and rinse the beaker thoroughly with water, adding 
the rinsings to the contents of the flask. Add enough saturated neutral lead acetate 
solution to produce a flocculent precipitate, shake thoroughly and allow to stand 15 
minutes. Make up to the mark with water, mix thorough'y, and filter through a 
dry filter. Add sufficient anhydrous sodium carbonate to the filtrate to precipitate 
all the lead, again filter through a dry paper and test the filtrate with a little anhy- 
drous sodium carbonate to make sure that all the lead has been removed. 

58 DETERMINATION OF REDUCING SUGARS. 

Proceed as directed under 26 or 29-34 respectively, employing the Soxhiet 
modification of Fehling's solution and using 25 cc. of the solution (representing 2 
grams of the sample), prepared as directed in 57. Express the results as dextrose 
or invert sugar. 

59 SUCROSE, 

Introduce 50 cc. of the solution, prepared as directed in 57, into a 100 cc. gradu- 
ated flask, add a piece of litmus paper, neutralize with acetic acid, add 5 cc. of con- 
centrated hydrochloric acid and allow the inversion to proceed at room temperature 
as directed under 14 or 16. When inversion is complete, transfer the solution to a 
beaker, neutralize with sodium carbonate, return the solution to Ih3 100 cc. flask, 
dilute to the mark with water, filter if necessary and determine reducing sugars in 
50 cc. of the solution (representing 2 grams of the sample) as directed in 58, and 
calculate the results as invert sugar. Subtract the per cent of reducing sugars be- 
fore inversion from the per cent of total sugar after inversion, both calculated as 
invert sugar, and multiply the difference by 0.95 to obtain the per cent of sucrose 
present. 

Since the insoluble material of grain or cattle food occupies some space in the 
flask as originally made up, it is necessary to correct for this volume. Results 
of a large number of determinations on various materials have shown the average 
volume of 12 grams of material to be 9 cc, and therefore to obtain the true amount 
of sugars present all results must be multiplied by the factor 0.97. 



110 METHODS OF ANALYSIS [Chap. 

STARCH. 

60 Direct Acid Hydrolysis (Modified Sachsse Method). — Official. 

(In this method there will be included as starch the pentosans and other carbo- 
hydrate bodies present which undergo hydrolysis and conversion into reducing 
sugars on boiling with hydrochloric acid.) 

Stir a quantity of the sample, representing 2.5-3 grams of the dry material, in a 
beaker with 50 cc. of cold water for an hour. Transfer to a filter and wash with 
250 cc. of cold water. Heat the insoluble residue for 2| hours with 200 cc. of water 
and 20 cc. of hydrochloric acid (sp. gr. 1.125) in a flask provided with a reflux con- 
denser. Cool, and nearly neutralize with sodium hydroxid. Complete the volume 
to 250 cc, filter, and determine the dextrose in an aliquot of the filtrate as directed 
under 52 or 54. The weight of the dextrose obtained multiplied by 0.90 gives the 
weight of starch. 

The factor 0.9 is the theoretical ratio between starch and glucose but, according 
to Noyes^and other investigators, the factor 0.93 more nearly approaches the actual 
yield. 

Diastase Method with Subsequent Acid Hydrolysis. — Tentative. 

61 REAGENT. 

Malt extract. — Digest 10 grams of fresh, finely ground malt for 2-3 hours at or- 
dinary temperature with 200 cc. of water and filter. Determine the amount of dex- 
trose in a given quantity of the filtrate after boiling with acid, etc., as in the starch 
determination, and make the proper correction in the subsequent determination. 

62 DETERMINATION. 

Extract a convenient quantity of the substance (ground to an impalpable powder 
and representing 4-5 grams of the dry material) on a hardened filterwith 5 successive 
portions of 10 cc. of ether ; wash with 150 cc. of 10% alcohol and then with a little strong 
alcohol. Place the residue in a beaker with 50 cc. of water, immerse the beaker in boil- 
ing water, and stir constantly for 15 minutes or until all the starch is gelatinized ; cool 
to 55°C., add 20 cc. of malt extract, and maintain at this temperature for an hour.. 
Heat again to boiling for a few minutes, cool to 55°C., add 20 cc. of malt extract, and 
maintain at this temperature for an hour or until the residue treated with iodin shows 
no blue color upon microscopic examination. Cool, make up directly to 250 cc, and 
filter. Place 200 cc. of the filtrate in a flask with 20 cc. of hydrochloric acid (sp. gr. 
1.125) ; connect with a reflux condenser and heat in a boiling water bath for 2J hours. 
Cool, nearly neutralize with sodium hydroxid solution, finish the neutralization 
with sodium carbonate solution, and make up to 500 cc. Mix the solution well, pour 
through a dry filter, and determine the dextrose in an aliquot as directed under 
52 or 54, Conduct a blank determination upon the same volume of the malt 
extract as used upon the sample and correct the weight of reduced copper accord- 
ingly. The weight of the dextrose obtained multiplied by 0.90 gives the weight of 
starch. 

PENTOSANS.— TENTATIVE. 

63 REAGENT. 

Phloroglucin. — Dissolve a small quantity of the phloroglucin in a few drops of 
acetic anhydrid, heat almost to boiling, and add a few drops of concentrated sul- 



VIII] FOODS AND FEEDING STUFFS 111 

phuric acid. A violet color indicates the presence of diresorcin. A phloroglucin 
which gives more than a faint coloration may be purified by the following method: 
Heat in a beaker about 300 cc. of hyd ochloric acid (sp. gr. 1.06) and 11 grams of 
commercial phloroglucin, added in small quantities at a time, stirring constantly 
until it has almost entirely dissolved. Pour the hot solution into a sufficient quan- 
tity of the same hydrochloric acid (cold) to make the volume 1500 cc. Allow it 
to stand at least overnight, preferably several days, to permit the diresorcin to 
crystallize out. Filter immediately before using. A yellow tint does not inter- 
fere with its usefulness. In using it, add the volume containing the required amount 
to the distillate. 

64 DETERMINATION. 

Place a quantity of the material, 2-5 grams, chosen so that the weight of phloro- 
glucid obtained shall not exceed 0.300 gram, in a 300 cc. distillation flask, together 
with 100 cc. of 12% hydrochloric acid (sp. gr. 1.06), and several pieces of recently 
heated pumice stone. Place the flask on a wire gauze, connect with a condenser, 
and heat, rather gently at first, and regulate so as to distil over 30 cc. in about 10 
minutes, the distillate passing through a small filter paper. Rep'ace the 30 cc. 
distilled by a like quantity of the dilute acid, added by means of a separatory funnel 
in such a manner as to wash down the particles adhering to the sides of the flask, and 
continue the process until the distillate amounts to 360 cc. To the total distillate 
add gradually a quantity of phloroglucin dissolved in 12% hydrochloric acid and 
stir thoroughly the resulting mixture. The amount of phloroglucin used should be 
about double that of the furfural expected. The solution turns first yellow, then 
green, and very soon an amorphous greenish precipitate appears, which grows 
darker rapidly, till it becomes finally almost black. Make the solution up to 400 
cc. with 12% hydrochloric acid, and allow to stand overnight. 

Filter the amorphous black precipitate into a tared Gooch crucible through an 
asbestos mat, wash carefully with 150 cc. of water in such a way that the water is 
not entirely removed from the crucible until the very last, then dry for 4 hours at 
the temperature of boiling water, cool and weigh in a weighing bottle, the increase 
in weight being reckoned as furfural phloroglucid. To calculate the furfural, pen- 
tose, or pentosan from the phloroglucid, use the following formulas given by Krober: 

(1) For a weight of phloroglucid, designated by "a" in the following formulas, 
under 0.03 gram. 

Furfural = (a + 0.0052) X 0.5170. 

Pentoses = (a + 0.0052) X 1.0170. 

Pentosans = (a + 0.0052) X 0.8949. 

In the above and also in the following formulas, the factor 0.0052 represents the 
weight of phloroglucid which remains dissolved ii the 403 cc. of acid solution. 

(2) For a weight of phloroglucid "a" over 0.300 gram. 

Furfural = (a + 0.0052) X 0.5180. 

Pentoses = (a + 0.0052) X 1.0026. 

Pentosans = (a + 0.0052) X 0.8824. 

For a weight of phloroglucid "a" between 0.03 and 0.300 gram use Krober's 
table, 65, or the following formulas in which the factors were calculated from 
Krober's tables by C. A. Browne, '' 

Furfural = (a + 0.0052) X 0.5185. 

Pentoses = (a + 0.0052) X 1.0075. 

Pentosans = (a + 0.0052) X 0.8866. 



112 
65 



methods of analysis 

Table 8.— Krober-s Table." 
For Determining Pentoses and Pentosans. 

[Expressed in grams.) 



[Chap. 



FURFURAL 
PHLOROG LUCID 


FURFURAL 


ARABINOSE 


ARABAN 


XYLOSE 


XYLAN 


PENTOSE 


PENTOSAN 


0.030 


0.0182 


0.0391 


0.0344 


0.0324 


0.0285 


0.0358 


0.0315 


0.031 


0.0188 


0.0402 


0.0354 


0.0333 


0.0293 


0.0368 


0.0324 


0.032 


0.0103 


0.0413 


0.0363 


0.0342 


0.0301 


0.0378 


0.0333 


0.033 


0.0198 


0.0424 


0.0373 


0.0352 


0.0309 


0.0388 


0.0341 


0.034 


0.0203 


0.0435 


0.0383 


0.0361 


0.0317 


0.0398 


0.0350 


0.035 


0.0209 


0.0446 


0.0393 


0.0370 


0.0326 


0.0408 


0.0359 


0.036 


0.0214 


0.0457 


0.0402 


0.0379 


0.0334 


0.0418 


0.0368 


0.037 


0.0219 


0.0468 


0.0412 


0.0388 


0.0342 


0.0428 


0.0377 


0.038 


0.0224 


0.0479 


0.0422 


0.0398 


0.0350 


0.0439 


0.0386 


0.039 


0.0.29 


.0490 


0.0431 


0.0407 


0.0358 


0.0449 


0.0395 


0.040 


0.0235 


0.0501 


0.0441 


0.0416 


0.0366 


0.0459 


0.0404 


0.041 


0.0240 


0.0512 


0.0451 


0.0425 


0.0374 


0.0469 


0.0413 


0.042 


0.0245 


0.0523 


0.0460 


0.0434 


0.0382 


0.0479 


0.0422 


0.043 


0.0250 


0.0534 


0.0470 


0.0443 


0.0390 


0.0489 


0.0431 


0.044 


0.0255 


0.0545 


0.0480 


0.0452 


0.0398 


0.0499 


0.0440 


0.045 


0.0260 


0.0556 


0.0490 


0.0462 


0.0406 


0.0509 


0.0448 


0.046 


0.0266 


0.0567 


0.0499 


0.0471 


0.0414 


0.0519 


0.0457 


0.047 


0.0271 


0.0578 


0.0509 


0.0480 


0.0422 


0.0529 


0.0466 


0.048 


0.0276 


0.0589 


0.0519 


0.0489 


0.0430 


0.0539 


0.0475 


0.049 


.0281 


0.0600 


0.0528 


0.0498 


0.0438 


0.0549 


0.0484 


0.050 


0.0286 


0.0611 


0.0538 


0.0507 


0.0446 


0.0559 


0.0492 


0.051 


0.0292 


0.0622 


0.0548 


0.0516 


0.0454 


0.0569 


0.0501 


0.052 


0.0297 


0.0633 


0.0557 


0.0525 


0.0462 


0.0579 


0.0510 


0.053 


0.0302 


0.0644 


0.0567 


0.0534 


0.0470 


0.0589 


0.0519 


0.054 


0.0307 


0.0655 


0.0576 


0.0543 


0.0478 


0.0599 


0.0528 


0.055 


0.0312 


0.0666 


0.0586 


0.0553 


0.0486 


0.0610 


0.0537 


0.056 


0.0318 


0.0677 


0.0596 


0.0562 


0.0494 


0.0620 


0.0546 


0.057 


0.0323 


0.0688 


0.0605 


0.0571 


0.0502 


0.0630 


0.0555 


0.058 


0.0328 


0.0699 


0.0615 


0.0580 


0510 


0.0640 


0.0564 


0.059 


0.0333 


0.0710 


0.0624 


0.0589 


0.0518 


0.0650 


0.0573 


0.060 


0.0338 


0.0721 


0.0634 


0.0598 


0.0526 


0.0660 


0.0581 


0.061 


0.0344 


0.0732 


0.0644 


0.0607 


0.0534 


0.0670 


0.0590 


0.062 


0.0349 


0.0743 


0.0653 


0.0616 


0.0542 


0.0680 


0.0599 


0.063 


0.0354 


0.0754 


0.0663 


0.0626 


0.0550 


0.0690 


0.0608 


0.064 


0.0359 


0.0765 


0.0673 


0.0635 


0.0558 


0.0700 


0.0617 


0.065 


0.0364 


0.0776 


0.0683 


0.0644 


0.0567 


0.0710 


0.0625 


0.066 


0.0370 


0.0787 


0.0692 


0.0653 


0.0575 


0.0720 


0.0634 


0.067 


0.0375 


0.0798 


0.0702 


0.0662 


0.0583 


0.0730 


0.0643 


0.068 


0.0380 


0.0809 


0.0712 


0.0672 


0.0591 


0.0741 


0.0652 


0.069 


0.0385 


0.0820 


0.0721 


0.0681 


0.0599 


0.0751 


0.0661 


0.070 


0.0390 


0.0831 


0.0731 


0.0690 


0.0607 


0.0761 


0.0670 


0.071 


0.0396 


0.0842 


0.0741 


0.0699 


0.0615 


0.0771 


0.0679 


0.072 


0.0401 


0.0853 


0.0750 


0.0708 


0.0623 


0.0781 


0.06S8 


0.073 


0.0406 


0.0864 


0.0760 


0.0717 


0.0631 


0.0791 


0.0697 


0.074 


0.0411 


0.0875 


0.0770 


0.0726 


0.0639 


0.0801 


0.0706 



VIII] 
65 



FOODS AND FEEDING STUFFS 

Table 8.— Krober's Table. — Continued. 

[Expressed in 'grams.] 



113 



rURFURAL 


FURFURAL 


ARABINCjSE 


AKABAN 


XYLOSE 


XYLAN 


PENTOSE 


PENTOSAN 


PHLOROQI.UCID 
















0.075 


0.0416 


0.0886 


0.0780 


0.0736 


0.0647 


0.0811 


0.0714 


0.076 


0.0422 


0.0897 


0.0789 


0.0745 


0.0655 


0.0821 


0.0722 


0.077 


0.0427 


0.0908 


0.0799 


0.0754 


0.0663 


0.0831 


0.0731 


0.078 


0.0432 


0.0919 


0.0809 


0.0763 


0.0671 


0.0841 


0.0740 


0.079 


0.0437 


0.0930 


0.0818 


0.0772 


0.0679 


0.0851 


0.0749 


0.080 


0.0442 


0.0941 


0.0828 


0.0781 


0.0687 


0.0861 


0.0758 


0.081 


0.0448 


0.0952 


0.0838 


0.0790 


0.0695 


0.0871 


0.0767 


0.082 


0.0453 


0.0963 


0.0847 


0.0799 


0.0703 


0.0881 


0.0776 


0.083 


0.0458 


0.0974 


0.0857 


0.0808 


0.0711 


0.0891 


0.0785 


0.084 


0.0463 


0.0985 


0.0867 


0.0817 


0.0719 


0.0901 


0.0794 


0.085 


0.0468 


0.0996 


0.0877 


0.0827 


0.0727 


0.0912 


0.0803 


0.086 


0.0474 


0.1007 


0.0886 


0.0836 


0.0735 


0.0922 


0.0812 


0.087 


0.0479 


0.1018 


0.0896 


0.0845 


0.0743 


0.0932 


0.0821 


0.088 


0.0484 


0.1029 


0.0906 


0.0854 


0.0751 


0.0942 


0.0830 


0.089 


0.0489 


0.1040 


0.0915 


0.0863 


0.0759 


0.0952 


0.0838 


0.090 


0.0494 


0.1051 


0.0925 


0.0872 


0.0767 


0.0962 


0.0847 


0.091 


0.0499 


0.1062 


0.0935 


0.0881 


0.0775 


0.0972 


0.0856 


0.092 


0.0505 


0.1073 


0.0944 


0.0890 


0.0783 


0.0982 


0.0865 


0.093 


0.0510 


0.1084 


0.0954 


0.0900 


0.0791 


0.0992 


0.0874 


0.094 


0.0515 


0.1095 


0.0964 


0.0909 


0.0800 


0.1002 


0.0883 


0.095 


0.0520 


0.1106 


0.0974 


0.0918 


0.0808 


0.1012 


0.0891 


0.096 


0.0525 


0.1117 


0.0983 


0.0927 


0.0816 


0.1022 


0.0899 


0.097 


0.0531 


0.1128 


0.0993 


0.0936 


0.0824 


0.1032 


0.0908 


0.098 


0.0536 


0.1139 


0.1003 


0.0946 


0.0832 


0.1043 


0.0917 


0.099 


0.0541 


0.1150 


0.1012 


0.0955 


0.0840 


0.1053 


0.0926 


0.100 


0.0546 


0.1161 


0.1022 


0.0964 


0.0848 


0.1063 


0.0935 


0.101 


0.0551 


0.1171 


0.1032 


0.0973 


0.0856 


0.1073 


0.0944 


0.102 


0.0557 


0.1182 


0.1041 


0.0982 


0.0864 


0.1083 


0.0953 


0.103 


0.0562 


0.1193 


0.1051 


0.0991 


0.0872 


0.1093 


0.0962 


0.104 


0.0567 


0.1204 


0.1060 


0.1000 


0.0880 


0.1103 


0.0971 


0.105 


0.0572 


0.1215 


0.1070 


0.1010 


0.0888 


0.1113 


0.0979 


0.106 


0.0577 


0.1226 


0.1080 


0.1019 


0.0896 


0.1123 


0.0988 


0.107 


0.0582 


0.1237 


0.1089 


0.1028 


0.0904 


0.1133 


0.0997 


0.108 


0.0588 


0.1248 


0.1099 


0.1037 


0.0912 


0.1143 


0.1006 


0.109 


0.0593 


0.1259 


0.1108 


0.1046 


0.0920 


0.1153 


0.1015 


0.110 


0.0598 


0.1270 


0.1118 


0.1055 


0.0928 


0.1163 


0.1023 


0.111 


0.0603 


0.1281 


0.1128 


0.1064 


0.0936 


0.1173 


0.1032 


0.112 


0.0608 


0.1292 


0.1137 


0.1073 


0.0944 


0.1183 


0.1041 


0.113 


0.0614 


0.1303 


0.1147 


0.1082 


0.0952 


0.1193 


0.1050 


0.114 


0.0619 


0.1314 


0.1156 


0.1091 


0.0960 


0.1203 


0.1059 


0.115 


0.0624 


0.1325 


0.1166 


0.1101 


0.0968 


0.1213 


0.1067 


0.116 


0.0629 


0.1336 


0.1176 


0.1110 


0.0976 


0.1223 


0.1076 


0.117 


0.0634 


0.1347 


0.1185 


0.1119 


0.0984 


0.1233 


0.1085 


0.118 


0.0640 


0.1358 


0.1195 


0.1128 


0.0992 


0.1243 


0.1094 


0.119 


0.0645 


0.1369 


0.1204 


0.1137 


0.1000 


0.1253 


0.1103 



114 
65 



METHODS OF ANALYSIS 

Tablio 8.— Krober'S Table.— Continued. 

lExproesed in grama.] 



[Chap. 



FURFURAl 
















PHLDROOl.UCID 


FURFURAL 


ARABIN08E 


ARABAN 


XYLOSB 


XYI.AN 


PENTOSE 


PENTOSAN 


0.120 


0.0650 


0.1380 


0.1214 


0.1146 


0.1008 


0.1263 


0.1111 


0.121 


0.0655 


0.1301 


0.1224 


0.1155 


0.1016 


0.1273 


0.1120 


0.122 


0.0660 


0.1402 


0.1233 


0.1164 


0.1024 


0.1283 


0.1129 


0.123 


0.0665 


0.1413 


0.1243 


0.1173 


0.1032 


0.1203 


0.1138 


0.124 


0.0671 


0.1424 


0.1253 


0.1182 


0.1040 


0.1303 


0.1147 


0.125 


0.0676 


0.1435 


0.1263 


0.1192 


0.1049 


0.1314 


0.1156 


0.1 2G 


0.0681 


0.1446 


0.1272 


0.1201 


0.1057 


0.1324 


0.1165 


0.127 


0.0686 


0.1457 


0.1282 


0.1210 


0.1065 


0.1334 


0.1174 


0.128 


0.0601 


0.1468 


0.1202 


0.1219 


0.1073 


0.1344 


0.1183 


0.129 


0.0697 


0.1479 


0.1301 


0.1228 


0.1081 


0.1354 


0.1192 


0.130 


0.0702 


1400 


0.1311 


0.1237 


0.1089 


0.1364 


0.1201 


0.131 


0.0707 


0.1501 


0.1321 


0.1246 


0.1097 


0.1374 


0.1210 


0.132 


0.0712 


0.1512 


0.1330 


0.1255 


0.1105 


0.1384 


0.1219 


0.133 


0.0717 


0.1523 


0.1340 


0.1264 


0.1113 


0.1304 


0.1227 


0.134 


0.0723 


0.1534 


0.1350 


0.1273 


0.1121 


0.1404 


0.1236 


0.135 


0.0728 


0.1545 


0.1360 


0.1283 


0.1120 


0.1414 


0.1244 


0.136 


0.0733 


0.1556 


0.1369 


0.1292 


0.1137 


0.1424 


0.1253 


0.137 


0.0738 


0.1567 


0.1379 


0.1301 


0.1145 


0.1434 


0.1262 


138 


0.0743 


0.1578 


0.1389 


0.1310 


0.1153 


0.1444 


0.1271 


0.139 


0.0748 


0.1589 


0.1398 


0.1319 


0.1161 


0.1454 


0.1280 


0.140 


0.0754 


0.1600 


0.1408 


0.1328 


0.1160 


0.1464 


0.1288 


0.141 


0.0750 


0.1611 


0.1418 


0.1337 


0.1177 


0.1474 


0.1207 


0.142 


0.0764 


0.1622 


0.1427 


0.1346 


0.1185 


0.1484 


0.1306 


0.143 


0.0760 


0.1633 


0.1437 


0.1355 


0.1103 


0.1404 


0.1315 


0.144 


0.0774 


0.1644 


0.1447 


0.1364 


0.1201 


0.1504 


0.1324 


0.145 


0.0780 


0.1655 


0.1457 


0.1374 


0.1200 


0.1515 


0.1333 


0.146 


0.0785 


0.1666 


0.1466 


0.1383 


0.1217 


0.1525 


0.1342 


0.147 


0.0700 


0.1677 


0.1476 


0.1392 


0.1225 


0.1535 


0.1351 


0.148 


0.0705 


0.1688 


0.1486 


0.1401 


0.1233 


0.1545 


0.1360 


0.149 


0.0800 


0.1699 


0.1495 


0.1410 


0.1241 


0.1555 


0.1369 


0.150 


0.0805 


0.1710 


0.1505 


0.1419 


0.1240 


0.1565 


0.1377 


0.151 


0.0811 


0.1721 


0.1515 


0.1428 


0.1257 


0.1575 


0.1386 


0.152 


0.0816 


0.1732 


0.1524 


0.1437 


0.1265 


0.1585 


0.1395 


0.153 


0.0821 


0.1743 


0.1534 


0.1446 


0.1273 


0.1505 


0.1404 


0.154 


0.0826 


0.1754 


0.1544 


0.1455 


0.1281 


0.1605 


0.1413 


0.155 


0.0831 


0.1765 


0.1554 


0.1465 


0.1280 


0.1615 


0.1421 


0.156 


0.0837 


0.1776 


0.1563 


0.1474 


0.1207 


0.1625 


0.1430 


0.157 


0.0842 


0.1787 


0.1573 


0.1-183 


0.1305 


0.1635 


0.1439 


0.158 


0.0847 


. 1798 


0.1583 


0.1492 


0.1313 


0.1645 


0.1448 


0.159 


0.0852 


0.1809 


0.1592 


0.1501 


0.1321 


0.1655 


0.1457 


0.160 


0.0857 


0.1820 


0.1602 


0.1510 


0.1329 


0.1665 


0.1465 


0.161 


0.0863 


0.1831 


0.1612 


0.1519 


0.1337 


0.1675 


0.1474 


0.162 


0.0868 


0.1842 


0.1621 


0.1528 


0.1345 


0.1685 


0.1483 


0.163 


0.0873 


0.1 S53 


0.1631 


0.1537 


0.1353 


0.1605 


0.1492 


0.164 


0.0878 


0.1864 


0.1640 


0.1546 


0.1361 


0.1705 


0.1501 



vni] 

65 



FOODS AND FEEDING STUFFS 

Table S.— Krober's Table.— Continued. 

[Expressed in grams.) 



115 



rnRFDBA.L 
PHl.OROai.UCID 


FURFUR.VL 


ARA.B1N0SE 


AR.<B.\.N 


XYLOSE 


XYLAN 


PENTOSE 


PBNTOS.i.N 


0.165 


0.0883 


0.1875 


0.1650 


0.1556 


0.1369 


0.1716 


0.1510 


0.166 


0.0888 


0.1886 


0.1600 


0.1565 


0.1377 


0.1726 


0.1519 


0.167 


0.0894 


0.1897 


0.1669 


0.1574 


0.1385 


0.1736 


0.1528 


0.168 


0.0899 


0.1908 


0.1679 


0.1583 


0.1393 


0.1746 


0.1537 


0.169 


0.0904 


0.1919 


0.1688 


0.1592 


0.1401 


0.1756 


0.1546 


0.170 


0.0909 


0.1930 


0.1698 


0.1601 


0.1409 


0.1766 


0.1554 


0.171 


0.0914 


0.1941 


0.1708 


0.1610 


0.1417 


0.1776 


0.1563 


0.172 


0,0920 


. 1952 


0.1717 


0.1619 


0.1425 


0.1786 


0.1572 


0.173 


0.0925 


0.1963 


0.1727 


0.1628 


. 1433 


0.1796 


0.1581 


0.174 


0.0930 


0.1974 


0.1736 


0.1637 


0.1441 


0.1806 


0.1590 


0.175 


0.0935 


0.1985 


0.1746 


0.1647 


0.1449 


0.1816 


0.1598 


0.176 


0.0940 


. 1996 


0.1756 


0.1656 


0.1457 


. 1826 


0.1607 


0.177 


0.0946 


0.2007 


0.1765 


0.1665 


0.1465 


0.1836 


0.1616 


0.178 


0.0951 


0.2018 


0.1775 


0.1674 


0.1473 


0.1846 


0.1625 


0.179 


0.0956 


0.2029 


0.1784 


0.1083 


0.1481 


0.1856 


0.1634 


O.ISO 


0.0961 


0.2039 


0.1794 


0.1692 


0.1489 


0.1866 


0.1642 


0.181 


0.0966 


0.2050 


0.1804 


0.1701 


0.1497 


0.1876 


0.1651 


0.182 


0.0971 


0.2061 


0.1813 


0.1710 


0.1505 


0.1886 


0.1660 


0.183 


0.0977 


0.2072 


0.1823 


0.1719 


0.1513 


0.1896 


0.1669 


0.184 


0.0982 


0.2082 


0.1832 


0.1728 


0.1521 


0.1906 


0.1678 


0.185 


0.0987 


0.2093 


0.1842 


0.1738 


0.1529 


0.1916 


0.1686 


0.186 


0.0992 


0.2104 


0.1851 


0.1747 


0.1537 


0.1926 


0.1695 


0.187 


0.0997 


0.2115 


0.1861 


0.1756 


0.1545 


0.1936 


0.1704 


0.188 


0.1003 


0.2126 


0.1870 


0.1765 


0.1553 


0.1946 


0.1712 


0.189 


0.1008 


0.2136 


O.ISSO 


0.1774 


0.1561 


0.1955 


0.1721 


0.190 


0.1013 


0.2147 


0.1889 


. 1783 


0.1569 


0.1965 


0.1729 


0.191 


0.1018 


0.2158 


. 1899 


. 1792 


0.1577 


0.1975 


0.1738 


0.192 


0.1023 


0.2168 


. 1908 


0.1801 


0.1585 


0.1985 


0.1747 


0.193 


0.1028 


0.2179 


0.1918 


0.1810 


0.1593 


0.1995 


0.1756 


0.194 


0.1034 


0.2190 


0.1927 


0.1819 


0.1601 


0.2005 


0.1764 


0.195 


0.1039 


0.2201 


0.1937 


0.1829 


0.1609 


0.2015 


0.1773 


0.196 


0.1044 


0.2212 


0.1946 


0.1838 


0.1617 


0.2025 


0.1782 


0.197 


0.1049 


0.2222 


0.1956 


0.1847 


0.1625 


0.2035 


0.1791 


0.198 


0.1054 


0.2233 


0.1965 


0.1856 


0.1633 


0.2045 


0.1800 


0.199 


0.1059 


0.2244 


0.1975 


0.1865 


0.1641 


0.2055 


0.1808 


0.200 


0.1065 


0.2255 


0.1984 


0.1874 


0.1649 


0.2065 


0.1817 


0.201 


0.1070 


0.2266 


0.1994 


0.1883 


0.1657 


0.2075 


0.1826' 


0.202 


0.1075 


0.2276 


0.2003 


0.1892 


0.1665 


0.2085 


0.1835 


0.203 


0.1080 


0.2287 


0.2013 


0.1901 


0.1673 


0.2095 


0.1844 


0.204 


0.1085 


0.2298 


0.2022 


0.1910 


0.1681 


0.2105 


0.1853 


0.205 


0.1090 


0.2309 


0.2032 


0.1920 


0.1689 


0.2115 


0.1861 


0.206 


0.1096 


0.2320 


0.2041 


0.1929 


. 1697 


0.2125 


0.1869 


0.207 


o.nni 


0.2330 


0.2051 


. 1938 


0.1705 


0.2134 


0.1878 


0.208 


0.1106 


0.2341 


0.2060 


0.1947 


0.1713 


0.2144 


0.1887 


0.209 


0.1111 


0.2352 


0.2069 


0.1956 


0.1721 


0.2154 


0.1896 



116 
65 



METHODS OF ANALYSIS 

Table 8. — Krober's Table. — Continued. 



[Chap. 







[Expressed in 


grams.) 








FURFURAL 
PHLOROGLUCID 


FURFURAL 


ARABINOSE 


ARABAN 


XYLOSE 


XYLAN 


PENTOSE 


PENTOSAN 


0.210 


0.1116 


0.2363 


0.2079 


0.1965 


0.1729 


0.2164 


0.1904 


0.211 


0.1121 


0.2374 


0.2089 


0.1975 


0.1737 


0.2174 


0.1913 


0.212 


0.1127 


0.2384 


0.2098 


0.1984 


0.1745 


0.2184 


0.1922 


0.213 


0.1132 


0.2395 


0.2108 


0.1993 


0.1753 


0.2194 


0.1931 


0.214 


0.1137 


0.2406 


0.2117 


0.2002 


0.1761 


0.2204 


0.1940 


0.215 


0.1142 


0.2417 


0.2127 


0.2011 


0.1770 


0.2214 


0.1948 


0.216 


0.1147 


0.2428 


0.2136 


0.2020 


0.1778 


0.2224 


0.1957 


0.217 


0.1152 


0.2438 


0.2146 


0.2029 


0.1786 


0.2234 


0.1966 


0.218 


0.1158 


0.2449 


0.2155 


0.2038 


0.1794 


0.2244 


0.1974 


0.219 


0.1163 


0.2460 


0.2165 


0.2047 


0.1802 


0.2254 


0.1983 


0.220 


0.1168 


0.2471 


0.2174 


0.2057 


0.1810 


0.2264 


0.1992 


0.221 


0.1173 


0.2482 


0.2184 


0.2066 


0.1818 


0.2274 


0.2001 


0.222 


0.1178 


0.2492 


0.2193 


0.2075 


0.1826 


0.2284 


0.2010 


0.223 


0.1183 


0.2503 


0.2203 


0.2084 


0.1834 


0.2294 


0.2019 


0.224 


0.1189 


0.2514 


0.2212 


0.2093 


0.1842 


0.2304 


0.2028 


0.225 


0.1194 


0.2525 


0.2222 


0.2102 


0.1850 


0.2314 


0.2037 


0.226 


0.1199 


0.2536 


0.2232 


0.2111 


0.1858 


0.2324 


0.2046 


0.227 


0.1204 


0.2546 


0.2241 


0.2121 


0.1866 


0.2334 


0.2054 


0.228 


0.1209 


0.2557 


0.2251 


0.2130 


0.1874 


0.2344 


0.2063 


0.229 


0.1214 


0.2568 


0.2260 


0.2139 


0.1882 


0.2354 


0.2072 


0.230 


0.1220 


0.2579 


0.2270 


0.2148 


0.1890 


0.2364 


0.2081 


0.231 


0.1225 


0.2590 


0.2280 


0.2157 


0.1898 


0.2374 


0.2089 


0.232 


0.1230 


0.2600 


0.2289 


0.2166 


0.1906 


0.2383 


0.2097 


0.233 


0.1235 


0.2611 


0.2299 


0.2175 


0.1914 


0.2393 


0.2106 


0.234 


0.1240 


0.2622 


0.2308 


0.2184 


0.1922 


0.2403 


0.2115 


0.235 


0.1245 


0.2633 


0.2318 


0.2193 


0.1930 


0.2413 


0.2124 


0.236 


0.1251 


0.2644 


0.2327 


0.2202 


0.1938 


0.2423 


0.2132 


0.237 


0.1256 


0.2654 


0.2337 


0.2211 


0.1946 


0.2433 


0.2141 


0.238 


0.1261 


0.2665 


0.2346 


0.2220 


0.1954 


0.2443 


0.2150 


0.239 


0.1266 


0.2676 


0.2356 


0.2229 


0.1962 


0.2453 


0.2159 


0.240 


0.1271 


0.2687 


0.2365 


0.2239 


0.1970 


0.2463 


0.2168 


0.241 


0.1276 


0.2698 


0.2375 


0.2248 


0.1978 


0.2473 


0.2176 


0.242 


0.1281 


0.2708 


0.2384 


0.2257 


0.1986 


0.2483 


0.2185 


0.243 


0.1287 


0.2719 


0.2394 


0.2266 


0.1994 


0.2493 


0.2194 


0.244 


0.1292 


0.2730 


0.2403 


0.2275 


0.2002 


0.2503 


0.2203 


0.245 


0.1297 


0.2741 


0.2413 


0.2284 


0.2010 


0.2513 


0.2212 


0.246 


0.1302 


0.2752 


0.2422 


0.2293 


0.2018 


0.2523 


0.2220 


0.247 


0.1307 


0.2762 


0.2432 


0.2302 


0.2026 


0.2533 


0.2229 


0.248 


0.1312 


0.2773 


0.2441 


0.2311 


0.2034 


0.2543 


0.2238 


0.249 


0.1318 


0.2784 


0.2451 


0.2320 


0.2042 


0.2553 


0.2247 


0.250 


0.1323 


0.2795 


0.2460 


0.2330 


0.2050 


0.2563 


0.2256 


0.251 


0.1328 


0.2806 


0.2470 


0.2339 


0.2058 


0.2573 


0.2264 


0.252 


0.1333 


0.2816 


0.2479 


0.2348 


0.2066 


0.2582 


0.2272 


0.253 


0.1338 


0.2827 


0.2489 


0.2357 


0.2074 


0.2592 


0.2281 


0.254 


0.1343 


0.2838 


0.2498 


0.2366 


0.2C82 


0.2602 


0.2290 



vni] 

65 



FOODS AND FEEDING STUFFS 

Table 8.— Krober's Table.— Continued. 



117 







[Expressed in 


grams.) 








FURFURAL 
PHLOROGLUCID 


FURFURAL 


ARABINOSE 


ARABAN 


XYLOSE 


XYLAN 


PENTOSE 


PENTOSAN 


0.255 


0.1349 


0.2849 


0.2508 


0.2375 


0.2090 


0.2612 


0.2299 


0.256 


0.1354 


0.2860 


0.2517 


0.2384 


0.2098 


0.2622 


0.2307 


0.257 


0.1359 


0.2870 


0.2526 


0.2393 


0.2106 


0.2632 


0.2316 


0.258 


0.1364 


0.2881 


0.2536 


0.2402 


0.2114 


0.2642 


0.2325 


0.259 


0.1369 


0.2892 


0.2545 


0.2411 


0.2122 


0.2652 


0.2334 


0.260 


0.1374 


0.29"3 


0.2555 


0.2420 


0.2130 


0.2662 


0.2342 


0.261 


0.1380 


0.2914 


0.2565 


0.2429 


0.2138 


0.2672 


0.2351 


0.262 


0.1385 


0.2924 


0.2574 


0.2438 


0.2146 


0.2681 


0.2359 


0.263 


0.1390 


0.2935 


0.2584 


0.2447 


0.2154 


0.2691 


0.2368 


0.264 


0.1395 


0.2946 


0.2593 


0.2456 


0.2162 


0.2701 


0.2377 


0.265 


0.1400 


0.2957 


0.26"3 


0.2465 


0.2170 


0.2711 


0.2385 


0.266 


0.1405 


0.2968 


0.2612 


0.2474 


0.2178 


0.2721 


0.2394 


0.267 


0.1411 


0.2978 


0.2622 


0.2483 


0.2186 


0.2731 


0.2403 


0.268 


0.1416 


0.2989 


0.2631 


0.2492 


0.2194 


0.2741 


0.2412 


0.269 


0.1421 


0.3000 


0.2641 


0.2502 


0.2202 


0.2751 


0.2421 


0.270 


0.1426 


0.3011 


0.2650 


0.2511 


0.2210 


0.2761 


0.2429 


0.271 


0.1431 


0.3022 


0.2660 


0.2520 


0.2218 


0.2771 


0.2438 


0.272 


0.1436 


0.3132 


0.2669 


0.2529 


0.2226 


0.2781 


0.2447 


0.273 


0.1442 


0.3043 


0.2679 


0.2538 


0.2234 


0.2791 


0.2456 


0.274 


0.1447 


0.3054 


0.2688 


0.2547 


0.2242 


0.2801 


0.2465 


0.275 


0.1452 


0.3965 


0.2698 


0.2556 


0.2250 


0.2811 


0.2473 


0.276 


0.1457 


0.3076 


0.2707 


0.2565 


0.2258 


0.2821 


0.2482 


0.277 


0.1462 


0.3086 


0.2717 


0.2574 


0.2266 


0.2830 


0.2490 


0.278 


0.1467 


0.3097 


0.2726 


0.2583 


0.2274 


0.2840 


0.2499 


0.279 


0.1473 


0.3108 


0.2736 


0.2592 


0.2282 


0.2850 


0.2508 


0.280 


0.1478 


0.3119 


0.2745 


0.2602 


0.2290 


0.2861 


0.2517 


0.281 


0.1483 


0.3130 


0.2755 


0.2611 


0.2298 


0.2871 


0.2526 


0.282 


0.1488 


0.3140 


0.2764 


0.2620 


0.2306 


0.2880 


0.2534 


0.283 


0.1493 


0.3151 


0.2774 


0.2629 


0.2314 


0.2890 


0.2543 


0.284 


0.1498 


0.3162 


0.2783 


0.2638 


0.2322 


0.2900 


0.2552 


0.285 


0.1504 


0.3173 


0.2793 


0.2647 


0.2330 


0.2910 


0.2561 


0.286 


0.1509 


0.3184 


0.2802 


0.2656 


0.2338 


0.2920 


0.2570 


0.287 


0.1514 


0.3194 


0.2812 


0.2665 


0.2346 


0.2930 


0.2578 


0.288 


0.1519 


0.3205 


0.2821 


0.2674 


0.2354 


0.2940 


0.2587 


0.289 


0.1524 


0.3216 


0.2831 


0.2683 


0.2362 


0.2950 


0.2596 


0.290 


0.1529 


0.3227 


0.2840 


0.2693 


0.2370 


0.2960 


0.2605 


0.291 


0.1535 


0.3238 


0.2850 


0.2702 


0.2378 


0.2970 


0.2614 


0.292 


0.1540 


0.3248 


0.2859 


0.2711 


0.2386 


0.2980 


0.2622 


0.293 


0.1545 


0.3259 


0.2868 


0.2720 


0.2394 


0.2990 


0.2631 


0.294 


0.1550 


0.3270 


0.2878 


0.2729 


0.2402 


0.3000 


0.2640 


0.295 


0.1555 


0.3281 


0.2887 


0.2738 


0.2410 


0.3010 


0.2649 


0.296 


0.1560 


0.3292 


0.2897 


0.2747 


0.2418 


0.3020 


0.2658 


0.297 


0.1566 


0.3302 


0.2906 


0.2756 


0.2426 


0.3030 


0.2666 


0.298 


0.1571 


0.3313 


0.2916 


0.2765 


0.2431 


0.3040 


0.2675 


0.299 


0.1576 


0.3324 


0.2925 


0.2774 


0.2442 


0.3050 


0.2684 


0.300 


0.1581 


0.3335 


0.2935 


0.2784 


0.2450 


A on«Q 


0.2693 



118 METHODS OF ANALYSIS [Chap. 

66 GALACTAN.— TENTATIVE. 

Extract a convenient quantity of the substance, representing 2.5-3 grams of the 
dry material, on a hardened filter with 5 successive portions of 10 cc. of ether, place 
the extracted residue in a beaker, about 5.5 cm. in diameter and 7 cm. deep, together 
with 60 cc. of nitric acid of 1.15 sp. gr., and evaporate the solution to exactly one 
third its volume in a water bath at a temperature of 94°-96°C. After standing 24 
hours, add 10 cc. of water to the precipitate, and allow it to stand another 24 hours. 
The mucic acid has in the meantime crystallized, but it is mixed with considerable 
material only partially oxidized by the nitric acid. Filter the solution through filter 
paper, wash with 30 cc. of water to remove as much of the nitric acid as possible, 
and replace the filter and contents in the beaker. Add 30 cc. of ammonium car- 
bonate solution, consisting of 1 part ammonium carbonate, 19 parts water, and 1 
part strong ammonium hydroxid, and heat the mixture on a water bath, at 80°C., 
for 15 minutes, with constant stirring. The ammonium carbonate takes up the 
mucic acid, forming soluble ammonium mucate. Wash the filter paper and con- 
tents several times with hot water by decantation, passing the washings through a 
filter paper, to which finally transfer the material and thoroughly wash. Evapo- 
rate the filtrate to dryness over a water bath, avoiding unnecessary heating which 
causes decomposition, add 5 cc. of nitric acid of 1.15 sp. gr., stir thoroughly the 
mixture and allow to stand for 30 minutes. The nitric acid decomposes the am- 
monium mucate, precipitating the mucic acid; collect this on a tared filter or Gooch, 
wash with 10-15 cc. of water, then with 60 cc. of alcohol, and a number of times 
with ether, dry at the temperature of boiling water for 3 hours, and weigh. Mul- 
tiply the weight of the mucic acid by 1.33, which gives galactose, and multiply this 
product by 0.9 which gives galactan. 

CRUDE FIBER,— OFFICIAL. 

67 REAGENTS. 

(a) 1M% sulphuric acid solution. — Exact strength, determined by titration. 

(b) 1.25% sodium hydroxid solution. — Exact strength, determined by titration. 

68 DETERMINATION. 

Extract a quantity of the substance, representing about 2 grams of the dry 
materia', with ordinary ether, or use the residue from the determination of the ether 
extract. To this residue in a 500 cc. flask add 200 cc. of boiling 1.25% sulphuric 
acid; connect the flask with an inverted condenser, the tube of which passes only a 
short distance beyond the rubber stopper into the flask, or simply cover a tall coni- 
cal flask, which is well suited for this determination, with a watch glass or short 
stemmed funnel, boil at once and cont'nue boiling gently for 30 minutes. A blast 
of air conducted nto the flask will serve to reduce the frothing of the liquid. Filter 
through linen and wash with boiling water until the washings are no longer acid; 
rinse the substance back into the flask with 200 cc. of boiling, 1.25% solution of 
sodium hydroxid, free or nearly free from sodium carbonate boil at once, and con- 
tinue boi'.ing gently for 30 minutes as directed above for the treatment with acid, 
filter at once rapidly, and wash with boiling water until the washings are neutral. 
The last filtration may be performed upon a Gooch crucible, a linen filter, or a tared 
filter paper. If a linen filter is used, rinse the crude fiber, after washing is completed, 
into a flat-bottomed platinum dish by means of a jet of water; evaporate to dryness 
on a steam bath, dry to constant weight at 110°C., weigh, incinerate completely, 
and weigh again. The loss in weight is considered to be crude fiber. If a tared filter 



VIII] FOODS AND FEEDING STUFFS 119 

paper is used, weigh in a weighing bottle. In any case the crude fiber after drying 
to constant weight at 110°C. must be incinerated and the amount of the ash deducted 
from the original weight. 

69 WATER-SOLUBLE ACIDITY OF FEEDS.— TENTATIVE. 

Weigh 10 grams of the sample into a shaking bottle, add 200 cc. of water, and 
shake for 15 minutes. Filter the extract through a folded filter and take a 20 cc. 
aliquot (equivalent to 1 gram of sample) for the titration. Dilute with 50 cc. of 
water and titrate with N/10 sodium hydroxid, using phenolphthalein as indicator. 

In reporting the acidity of feeds, state the results in terms of cc. of N/10 sodium 
hydroxid required for neutralization. 

BIBLIOGRAPHY. 

» Z. Ver. Zucker-Ind., 1900, 37 (I): 357; 1913, 63 (I): 25; J. Ind. Eng. Chem., 
1913,5:167. 

2 J. Am. Chem. Soc. 1914, 36: 1566. 

3 Ibid., 1906, 28: 663; 1907, 29: 541. 
«Ibid., 1902, 24: 1082. 

» Z. Rubenzucker-Ind., 1885, 35 (N. F.22) : 1012. 
« Ibid., 1889, 39 (N. F. 26) : 734. 
' Ibid., 1879, 29 (N. F. 16) : 1034. 

* Wein. Tables for the Quantitative Estimation of the Sugars. Translated by 
Frew. 1896, p. 26. 
'Ibid., p. 33. 
1" Z. Rubenzucker-Ind., 1882, 32 (N. F. 19) : 606, 865. 

11 U.S. Bur. Chem. Circ. 71. 

12 J. Am. Chem. Soc, 1904. 26: 266. 
" U. S. Bur. Chem. Bull. 73, p. 173. 
"J. Landw., 1900, 4j: 379. 



IX. SACCKARINE PRODUCTS. 

1 PREPARATION OF SAMPLE.— TENTATIVE. 

(a) Liquids {molasses, sirups, etc.). — Mix materials of this class thoroughly. 
If crystals of sugar are present, dissolve them either by heating gently or by weigh- 
ing the whole mass, then adding water, heating until completely dissolved and 
after cooling, re-weighing. Calculate all results to the weight of the original 
substance. 

(b) Semisolids (jellies, jams, etc.). — Weigh 50 grams of the sample into a 250 
cc. graduated flask. Treat with water, fill to the mark and mix thoroughly. If 
insoluble material remains, mix uniformly by shaking before taking aliquots for 
the various determinations. 

(C) Solids {sugar, confectionery, etc.). — Grind and mix thoroughly materials 
of this class to secure uniform samples. 

Moisture. 

DRYING METHODS. 

2 SUGARS.— OFFICIAL. 

Dry 2-5 grams in a flat dish (nickel, platinum, or aluminium) at the temperature 
of boiling water for 10 hours; cool in a desiccator and weigh; then dry again for an 
hour or until there is only a slight change in weight. 

With some sugars, more especially those of large grain, there is danger of occlu- 
sion and retention of water. The International Commission for Unifying Methods 
of Sugar Analysis prescribe drying at 105°-110°C. for normal beet sugars. This 
temperature is sufficient to expel the last traces of occluded water and is not attended 
with sufficient decomposition to affect the weight of the product. The drying tem- 
perature should never exceed 110°C^ 

MASSECUITES, MOLASSES, AND OTHER LIQUID AND SEMILIQUID PRODUCTS. 

3 Drying upon Pumice Stone. — ^Tentative. 

Prepare pumice stone of two grades of fineness, one of which will pass through 
a 1 mm. sieve, the other through a 6 mm. sieve. Make the determination in flat 
metallic dishes or in shallow, flat-bottomed, weighing bottles. Place a layer of 
the fine pumice stone, 3 mm. in thickness, on the bottom of the dish, then a layer 
of the coarse pumice stone 6-10 mm. in thickness, dry and weigh. Dilute the sam- 
ple with a weighed portion of water so that the diluted material shall contain 20- 
30% of solid matter. Weigh into the dish, prepared as described above, an amount 
of the diluted sample to yield, approximately, 1 gram of dry matter. If this weigh- 
ing can not be made rapidly, use a weighing bottle provided with a cork through 
which a pipette passes. Dry in vacuo at 70°C. to constant weight, making trial 
weighings at intervals of 2 hours. For substances containing little or no levulose 
or other readily decomposable substance, the drying may be made in a water oven 
at the temperature of boiling water. 

4 Drying upon Quartz Sand. — Tentative. 

Digest pure quartz sand with strong hydrochloric acid, wash, dry, and ignite. 
Preserve in a stoppered bottle. 

121 



122 METHODS OF ANALYSIS [Chap. 

Place 6-7 grams of the prepared sand and a short stirring rod in a flat-bottomed 
dish. Dry thoroughly, cool in a desiccator, and weigh. Then add 3-4 grams of 
the molasses, mix with the sand (if necessary to thoroughly incorporate the two, 
add a little water), dry in a water oven at the temperature of boiling water 
for 8-10 hours, stirring at intervals of an hour, cool in a desiccator, and weigh. 
Stir, heat again for an hour, cool, and weigh. Repeat the heating and weighing 
until the loss of water in an hour is not greater than 3 mg. 

AREOMETRIC METHODS. 

(Not applicable to low-grade sugar products, molasses and other materials 
containing large amounts of non-sugar solids.) 

SPECIFIC GRAVITY, WATER AND TOTAL SOLIDS. 
5 By Means of a Spindle. — Official. 

The density of juices, sirups, etc., is most conveniently determined by means 
of the Brix hydrometer. For rough work, or where less accuracy is desired, the 
Baume hydrometer may be used. The Brix spindle should be graduated to tenths. 
The range of degrees recorded by each individual spindle should be as limited as 
possible. The solution should be as nearly as practicable of the same tempera- 
ture as the air at the time of reading, and, if the variation from the temperature 
of the graduation of the spindle amounts to more than 1°, a correction must be 
applied according to the table under 6. Before taking the density of a juice, allow 
it to stand in the cylinder until all air bubbles have escaped, and until all fatty or 
waxy matter has come to the surface and been skimmed off. The cylinder should 

be large enough in diameter to allow the hydrometer to come to rest without touch- 

20 "C 

ing the sides. A table of specific gravities at —^ and per cent by weight of suc- 
rose is given under 9, and a table for the comparison of specific gravities at ~[fj^ > 
degrees Brix (per cent by weight of sucrose), and degree Baum^ is given under 8. 

If the sample is too dense to determine the density directly, dilute a weighed 
portion with a weighed quantity of water, or dissolve a weighed portion and dilute 
to a known volume with water. 

In the first instance the per cent of total solids is calculated by the following 
formula: 

WS . 

Per cent of solids in the undiluted material = — in which 

w 

S = per cent of solids in the diluted material; 

W = weight of the diluted material; 

w = weight of the sample taken for dilution. 

When the dilution is made to a definite volume, the following formula is to be 
used: 

Per cent of solids in the undiluted material = „, in which 

W 

V = volume of the diluted solution at a given temperature; 
D = specific gravity of the diluted solution at the same temperature; 
S = per cent of solids in the diluted solution at the same temperature; 
W = weight of the sample taken for dilution at the same temperature. 

If the spindle reading be made at any other temperature than 17.5°C., the re- 
sult should be corrected according to the following: 



IX] 



SACCHARINE PRODUCTS 



123 



Table 9. 

For correction of the readings of the Brix spindle when made at other than the 
standard temperature, 17.5°C. 





(For 


temperatures below IT.S'C. the correction is to be subtracted.) 




TEM- 








DEGREE 


BRIX OP THE SOLUTION 










PERA- 




























TURE 





5 


10 


15 


20 


25 


30 


35 


40 


50 


60 


70 


75 


"C. 



0.17 


0.30 


0.41 


0.52 


0.62 


0.72 


0.82 


0.92 


0.98 


1.11 


1.22 


1.25 


1 29 


5 


0.23 


30 


0.37 


0.44 


0.52 


0.59 


0.65 


0.72 


0.75 


0.80 


88 


0.91 


94 


10 


20 


0.26 


0.29 


0.33 


0.36 


0.39 


0.42 


0.45 


0.48 


0.50 


0.54 


0.58 


0.61 


11 


0.18 


0.23 


0.26 


0.28 


0.31 


0.34 


0.36 


0.39 


0.41 


43 


0.47 


0.50 


0.53 


12 


0.16 


0.20 


22 


0.24 


0.26 


0.29 


0.31 


0.33 


0.34 


0.36 


0.40 


0.42 


0.46 


13 


0.14 


0.18 


19 


0.21 


0.22 


0.24 


0.26 


0.27 


0.28 


29 


0.33 


0.35 


0.39 


14 


0.12 


15 


16 


0.17 


0.18 


0.19 


0.21 


0.22 


0.22 


0.23 


0.26 


0.28 


0.32 


15 


0.09 


o.n 


12 


14 


0.14 


0.15 


0.16 


0.17 


0.16 


0.17 


0.19 


0.21 


0.25 


16 


OS 


0.07 


08 


0.09 


0.10 


10 


0.11 


0.12 


12 


0.12 


0.14 


0.16 


0.18 


17 


0.02 


0.02 


0.03 


0.03 


0.03 


0.04 


0.04 


0.04 


0.04 


0.04 


0.05 


0.05 


0.06 


18 


02 


0.03 


0.03 


0.03 


0.03 


0.03 


03 


03 


0.03 


0.03 


0.03 


0.03 


0.02 


19 


0.06 


O.OS 


08 


09 


09 


0.10 


0.10 


0.10 


0.10 


0.10 


0.10 


0.03 


0.06 


20 


on 


0.14 


15 


0.17 


17 


0.18 


0.18 


0.18 


0.19 


19 


0.18 


0.15 


0.11 


21 


0.16 


0.20 


0.22 


0.24 


0.24 


0.25 


0.25 


0.25 


0.26 


0.26 


0.25 


0.22 


0.18 


22 


0.21 


0.26 


0.29 


31 


0.31 


0.32 


0.32 


0.32 


0.33 


0.34 


0.32 


0.29 


0.25 


23 


0.27 


0.32 


35 


37 


0.38 


0.39 


0.39 


0.39 


0.40 


0.42 


0.39 


0.36 


0.33 


24 


32 


38 


0.41 


0.43 


44 


0.46 


0.46 


47 


0.47 


0.50 


0.46 


0.43 


0.40 


25 


0.37 


0.44 


0.47 


49 


0.51 


0.53 


0.54 


55 


0.55 


58 


0.54 


0.51 


0.48 


26 


0.43 


0.50 


0.54 


0.56 


0.58 


0.60 


0.61 


0.02 


62 


0.66 


0.62 


0.58 


0.55 


27 


0.49 


0.57 


0.01 


0.63 


0.65 


0.08 


0.68 


0.09 


0.70 


0.74 


0.70 


0.65 


0.62 


28 


0.56 


0.64 


0.68 


0.70 


0.72 


0.76 


0.76 


0.78 


0.78 


82 


0.78 


0.72 


0.70 


29 


0.63 


71 


0.75 


0.78 


0.79 


0.84 


0.84 


0.86 


0.86 


0.90 


0.86 


0.80 


0.78 


30 


0.70 


0.78 


0.82 


0.87 


0.87 


0.92 


0.92 


0.94 


0.94 


0.98 


0.94 


0.88 


0.86 


35 


1.10 


1.17 


1.22 


1.24 


1.30 


1.32 


1.33 


1.35 


1.36 


1.39 


1.34 


1.27 


1.25 


40 


1.50 


1 61 


1.67 


1.71 


1.73 


1 79 


1.79 


1.80 


1.82 


1.83 


1.78 


1.69 


1.65 


50 




2.65 


2.71 


2.74 


2.78 


2.80 


2.80 


2.80 


2.80 


2.79 


2.70 


2.56 


2.51 


60 




3.87 


3.88 


3.88 


3.88 


3.88 


3.88 


3.88 


3.90 


3.82 


3.70 


3.43 


3.41 


70 




5.17 


5.18 


5.20 


5.14 


5.13 


5.10 


5.08 


5.06 


4.90 


4.72 


4.47 


4.35 


80 






6.62 


6.59 


6.54 


6.46 


6.38 


6.30 


6.26 


6.06 


5 82 


5.50 


5.33 


90 






8.26 


8.16 


8.06 


7.97 


7.83 


7.71 


7.58 


7.30 


6.96 


6.58 


6.37 


100 






10.01 


9.87 


9.72 


9.56 


9.39 


9.21 


9.03 


8.64 


8.22 


7.76 


7.42 



Example. — A sugar solution shows a reading of 30.2° Brix at 30°C. To find the 
necessary correction for the conversion of this reading to the reading which would 
have been obtained if the observation had been made at 17.5°C., find the vertical 
column in the table headed 30° Erix, which is the nearest to the observed reading. 
Follow down this column until the number is reached which is opposite to the tem- 
perature of observation — in this case 30°. The number found, 0.92, is to be added 
to the observed reading. 



By Means of a Pycnometer. — Official. 



20°C. 



(a) By specific gravity at —^' — Determine the specific gravity of the solution 
at -^ ' by means of a pycnometer and ascertain the corresponding per cent bj 
weight of sucrose from 9. When the density of the substance is too high for a direct 
determination, dilute and calculate the sucrose content of the original material aa 
directed under 5. 

(b) By specific gravity at ^^ ^o' ■ — Proceed as directed under (a), the determina- 

Ascertain the corre- 



17 5°C 20°C 

tions of specific gravity being made at -[f^' instead of at -tf^ 

sponding per cent by weight of sucrose from 8. 

The pycnometer determination should not be made at any other temperature 

., 17.5°C. 20°C. 

than -jy-g^ or -^- 



124 



METHODS OF ANALYSIS 



[Chap. 



8 



Table 10. 

17. 5° C. 



For the comparison of specific gravities at ' o' , degrees Brix and degrees BaumS 



17.5'' 



Degree Baum6 = 146.78 



146.78 













sp.g 


r. 






DEGREE 






DEGREE 






DEGREE 






BBIX OR 






BRIX OR 






BRIX OR 






PER CENT 


SPECIFIC 


DEGREE 


PER CENT 


SPECIFIC 


DEGREE 


PER CENT 


SPECIFIC 


DEGREE 


BY 
WEIGHT 


GRAVITY 


baum£ 


BY 
WEIGHT 


GRAVITY 


BADM^ 


BY 

WEIGHT 


GRAVITY 


baum6 


OP 






OF 






OF 






8UCB0SE 






SUCROSE 






SUCROSE 






1.0 


1.00388 


0.6 


33.0 


1.14423 


18.5 


65.0 


1.31989 


35.6 


2.0 


1.00779 


1.1 


34.0 


1.14915 


19.05 


66.0 


1.32601 


36.1 


3.0 


1.01173 


1.7 


35.0 


1.15411 


19.6 


67.0 


1.33217 


36.6 


4.0 


1.01570 


2.3 


36.0 


1.15911 


20.1 


68.0 


1.33836 


37.1 


5.0 


1.01970 


2.8 


37.0 


1.16413 


20.7 


69.0 


1.34460 


37.6 


6.0 


1.02373 


3.4 


38.0 


1 . 16920 


21.2 


70.0 


1.35088 


38.1 


7.0 


1.02779 


4.0 


39.0 


1 . 17430 


21.8 : 


71.0 


1.35720 


38.6 


8.0 


1.03187 


4.5 


40.0 


1.17943 


22.3 


72.0 


1.36355 


39.1 


9.0 


1.03599 


5.1 


41.0 


1 . 18460 


22.9 


73.0 


1.36995 


39.6 


10.0 


1.04014 


5.7 


42.0 


1 . 18981 


23.4 


74.0 


1.37639 


40.1 


11.0 


1.04431 


6.2 


43.0 


1 . 19505 


23.95 


75.0 


1.38287 


40.6 


12.0 


1.04852 


6.8 


44.0 


1.20033 


24.5 


76.0 


1.38939 


41.1 


13.0 


1.05276 


7.4 


45.0 


1.20565 


25.0 


77.0 


1.39595 


41.6 


14.0 


1.05703 


7.9 


46.0 


1.21100 


25.6 


78.0 


1.40254 


42.1 


15.0 


1.06133 


8.5 


47.0 


1.21639 


26.1 


79.0 


1.40918 


42.6 


16.0 


1.06566 


9.0 


48.0 


1.22182 


26.6 


80.0 


1.41586 


43.1 


17.0 


1.07002 


9.6 


49.0 


1.22728 


27.2 


81.0 


1.42258 


43.6 


18.0 


1.07441 


10.1 


50.0 


1.23278 


27.7 


82.0 


1.42934 


44.1 


19.0 


1.07884 


10.7 


51.0 


1.23832 


28.2 


83.0 


1.43614 


44.6 


20.0 


1.08329 


11.3 


52.0 


1.24390 


28.8 


84.0 


1.44298 


45.1 


21.0 


1.08V78 


11.8 


53.0 


1.24951 


29.3 


85.0 


1.44986 


45.5 


22.0 


1.09231 


12.4 


54.0 


1.25517 


29.8 


86.0 


1.45678 


46.0 


23.0 


1.09686 


13.0 


55.0 


1.26086 


30.4 


87.0 


1.46374 


46.5 


24.0 


1 . 10145 


13.5 


56.0 


1.26658 


30.9 


88.0 


1.47074 


47.0 


25.0 


1.10607 


14.1 


57.0 


1.272.35 


31.4 


89.0 


1.47778 


47.45 


26.0 


1.11072 


14.6 


58.0 


1.27816 


31.9 


90.0 


1.48486 


47.9 


27.0 


1.11541 


15.2 


59.0 


1.28400 


32.5 


91.0 


1.49199 


48.5 


28.0 


1 . 12013 


15.7 


60.0 


1.28989 


33.0 


92.0 


1.49915 


48.9 


29.0 


1 . 12488 


16.3 


61.0 


1.29581 


33.5 


93.0 


1.50635 


49.4 


30.0 


1 . 12967 


16.8 


62.0 


1.30177 


34.0 


94.0 


1.51359 


49.8 


31.0 


1 . 13449 


17.4 


63.0 


1.30777 


34.5 


95.0 


1.52087 


50.3 


32.0 


1.13934 


17.95 


64.0 


1.31381 


35.1 









When the number expressing the specific gravity found by analysis falls between 
the numbers given in the above table, the exact equivalent in degrees Brix or Baume 
is found by a simple calculation. 

Example. — The pycnometer shows the specific gravity of a certain sirup to be 
1.20909. The table shows that the corresponding degree Brix is between 45.0 and 
46.0. Subtracting the specific gravity of a solution of 45° Brix from the correspond- 
ing figure for 46°, we have (expressing the specific gravities as whole numbers) 
121,100 - 120,565 = 535, the difference in specific gravity for 1° Brix at this point 
in the table. Subtracting the specific gravity corresponding to 45° from the spe- 

344 
cific gravity found by analysis, we have 120,909 - 120,565 = 344; ^ = 0.64, the frac- 
tion of 1° Brix more than 45°. The degree Brix, corresponding to a sp. gr. of 1.20909, 
is therefore 45.64. 



IX] 



SACCHARINE PRODUCTS 



125 



9 Table 11. 

Densities^ of solutions of cane sugar at 20°C 

(This table is the basis for standardizing hydrometers indicating per cent of suear 

at 20°C.) 





TENTHS OP PER CENT 




PER CENT 






SUQAR 





1 


2 


3 


4 


5 


6 


7 


8 


9 





0.998234 


0.998622 


0.99901C 


0.99939S 


0.999786 


1.000174 


1.000563 


1.000952 


1.001342 


1.001731 


1 


1.00212C 


1.002509 


1.002897 


1.003286 


1.003675 


1.004064 


1.004453 


1.004844 


1.005234 


1.005624 


2 


1.0060U 


1.00640 J 


1.006796 


1.007188 


1.007580 


1.007972 


1.008363 


1.008755 


1.009148 


1.009541 


3 


1.009934 


1.010327 


1.010721 


l.OllllS 


1.011510 


1.011904 


1.012298 


1.012694 


1.013089 


1.013485 


4 


1.013881 


1.014277 


1.014673 


1.01507C 


1.015167 


1.015864 


1.016261 


1.016659 


1.017058 


1.017456 


6 


1.017854 


1.018253 


1.018652 


1.019052 


1.019451 


1.019851 


1.020251 


1.020651 


1.021053 


1.021454 


6 


1.021855 


1.022257 


1.022659 


1.023061 


1.023463 


1.023867 


1.024270 


1.024673 


1.025077 


1.025481 


7 


1.025885 


1.026289 


1.026894 


1.027099 


1.027504 


1.027910 


1.028316 


1.028722 


1.029128 


1.029535 


8 


1.029942 


1.0.30349 


1.030757 


1.031165 


1.031573 


1.031982 


1.032391 


1.032800 


1.033209 


1.033619 


9 


1.034029 


1.034439 


1.034850 


1.035260 


1.035671 


1.036082 


1.036494 


1.036906 


1.037318 


1.037730 


10 


1.038143 


1.038556 


1.038970 


1.039383 


1.039797 


1.040212 


1.040626 


1.041041 


1.041456 


1.041872 


11 


1.042288 


1.042704 


1.043121 


1.043537 


1.043954 


1.041370 


1.044788 


1.045206 


1.045625 


1.046043 


12 


1.046462 


1.046881 


1.047300 


1.047720 


1.048140 


1.048559 


1.048980 


1.049401 


1.049822 


1 . 050243 


13 


1.050665 


1.051087 


1.051510 


1.051933 


1.052356 


1.052778 


1.053202 


1.053626 


1.054050 


1.054475 


14 


1.054900 


1.055325 


1.055751 


1.056176 


1.056602 


1.057029 


1.057455 


1.057882 


1.058310 


1.058737 


15 


1.059165 


1.059593 


1.060022 


1.060451 


1.060880 


1.061308 


1.061738 


1.062168 


1.062598 


1.063029 


16 


1.063460 


1.063892 


1.064324 


1.064756 


1.065188 


1.065621 


1.066054 


1.066487 


1.066921 


1.067355 


17 


1.067789 


1.068223 


1.068658 


1.069093 


1.069529 


1.069964 


1.070400 


1.070836 


1.071273 


1.071710 


18 


1.072147 


1.072585 


1.073023 


1.073461 


1.073900 


1.074338 


1.074777 


1.075217 


1.075657 


1.076097 


19 


1.076537 


1.076978 


1.077419 


1.077860 


1.078302 


1.078744 


1.079187 


1.079629 


1.080072 


1.080515 


20 


1.080959 


1.081403 


1.081848 


1.082292 


1.082737 


1.083182 


1.083628 


1.084074 


1.084520 


1.084967 


21 


1.085414 


1.085861 


1.086309 


1.086757 


1.087205 


1.087652 


1.088101 


1.088550 


1.089000 


1 . 089450 


22 


1.089900 


1.090351 


1.090802 


1.091253 


1.091704 


1.092155 


1.092607 


1.093060 


1.093513 


1.093966 


23 


1.094420 


1.094874 


1.095328 


1.095782 


1.096236 


1.096691 


1.097147 


1.097603 


1.098058 


1.098514 


24 


1.098971 


1.099428 


1.099886 


1.100344 


1.100802 


1.101259 


1.101718 


1.102177 


1.102637 


1.103097 


25 


1.103557 


1.104017 


1.104478 


1.104938 


1.105400 


1.105862 


1.106324 


1.106786 


1.107248 


1.107711 


26 


1.108175 


1.108639 


1.109103 


1 . 109568 


1.110033 


1.110497 


1.110963 


1.111429 


1.111895 


1.112361 


27 


1.11282S 


1.113295 


1.113763 


1.114229 


1.114697 


1.115166 


1.115635 


1.116104 


1.116572 


1.117042 


28 


1.117512 


1.117982 


1.118453 


1.118923 


1.119395 


1.119867 


1.120339 


1.120812 


1.121284 


1.121757 


29 


1.122231 


1.122705 


1.123179 


1.123653 


1.124128 


1.124603 


1.125079 


1.125555 


1.126030 


1.126507 


30 


1.126984 


1.127461 


1.1279.39 


1.128417 


1.128896 


1.129374 


1.129853 


1.130332 


1.130812 


1.131292 


31 


1.131773 


1.132254 


1.132735 


1.133216 


1.133698 


1.134180 


1.134663 


1.135146 


1.135628 


1.136112 


32 


1.136596 


1.137080 


1.137565 


1 . 138049 


1.138534 


1 . 139020 


1 . 139506 


1.139993 


1 . 140479 


1 . 140968 


33 


1.141453 


1.141941 


1.142429 


1.142916 


1 . 143405 


1.143894 


1.144384 


1.144874 


1.145363 


1 . 145854 


34 


1.146345 


1.146836 


1.147328 


1.147820 


1.148313 


1.148805 


1.149298 


1.149792 


1.150286 


1.150780 


35 


1.151275 


1.151770 


1.152265 


1.152760 


1.153256 


1.15.3752 


1.154249 


1.154746 


1.155242 


1.155740 


36 


1 . 156238 


1.156736 


1.157235 


1.157733 


1 . 158233 


1 . 158733 


1.159233 


1.159733 


1.160233 


1.160734 


37 


1.161236 


1.161738 


1.162240 


1.162742 


1.163245 


1 . 163748 


1.164252 


1.164756 


1.165259 


1.165764 


38 


1.166269 


1.166775 


1.167281 


1.167786 


1.168293 


1 . 168800 


1.169307 


1.169815 


1.170322 


1.170831 


39 


1.171340 


1.171849 


1.172359 


1.172869 


1.173379 


1.173889 


1.174400 


1.174911 


1.175423 


1.175935 


40 


1.176447 


1.176960 


1.177473 


1.177987 


1.178501 


1.179014 


1.179527 


1.180044 


1.180560 


1.181076 


41 


1.181592 


1.182108 


1.182625 


1.183142 


1.183660 


1.184178 


1.184696 


1.185215 


1.185734 


1 . 186253 


42 


1.186773 


1.187293 


1.187814 


1.188335 


1.188S56 


1.189379 


1.189901 


1.190423 


1.190916 


1.191469 


43 


1.191993 


1.192517 


1.193041 


1.193565 


1.194090 


1.194616 


1.195141 


1.195667 


1.196193 


1.196720 


44 


1.197247 


1.197775 


1.198303 


1.198832 


1.199360 


1.199890 


1.200420 


1.200950 


1.201480 


1.202010 


45 


1.202540 


1.203071 


1.203603 


1.204136 


1.204668 


1.205200 


1.205733 


1.206266 


1.206801 


1.207335 


46 


1.207870 


1.208405 


1.208940 


1.209477 


1.210013 


1.210549 


1.211086 


1.211623 


1.212162 


1.212700 


47 


1.213238 


1.213777 


1.214317 


1.214856 


1.215395 


1.215936 


1.216476 


1.217017 


1.217559 


1.218101 


48 


1.218643 


1.219185 


1.219729 


1.220272 


1.220815 


1.221360 


1.221904 


1.222449 


1.222995 


1.223540 


49 


1.224086 


1.224632 


1.225180 


1.225727 


1.226274 


1.226823 


1.227371 


1.227919 


1.228469 


1.229018 


50 


1.229567 


1.230117 


1.230668 


1.231219 


1.231770 


1.232322 


1.232874 


1.2,33426 


1.233979 


1.234532 


51 


1.235085 


1.235639 


1.236194 


1.236748 


1.237303 


1.237859 


1.238414 


1.238970 


1.239527 


1.240084 


52 


1.240641 


1.241198 


1.241757 


1.242315 


1.242873 


1.243433 


1.243992 


1.244552 


1.245113 


1.245673 


53 


1.246234 


1.246795 


1.247358 


1.247920 


1.248482 


1.249046 


1.249609 


1.250172 


1.250737 


1.251301 


54 


1.251866 


1.252431 


1.252997 


1.253563 


1.254129 


1.254697 


1.255264 


1.255831 


1.256400 


1.256967 


55 


1.257535 


1.258104 


1.258674 


1.259244 


1.259815 


1.260385 


1.260955 


1.261527 


1.262099 


1,262671 


56 


1.263243 


1.263816 


1.264390 


1.264963 


1.265537 


1.266112 


1.266686 


1.267261 


1.267837 


1.268413 


57 


1.268989 


1.269565 


1.270143 


1.270720 


1.271299 


1.271877 


1.272455 


1.273035 


1.273614 


1.274194 


58 


1.274774 


1.275354 


1.2759.36 


1.276517 


1.277098 


1.277680 


1.278262 


1.278844 


1.279428 


1.280011 


59 


1.280595 


1.281179 


1.281764 


1.282349 


1.282935 


1.283521 


1.284107 


1.284694 


1.285281 


1.285869 



126 
9 



METHODS OF ANALYSIS 

Table 11.— Continued. 
Densities of solutions of cane sugar at 20°C. 



[Chap. 



PER CENT 
eCUAR 



60 
61 
62 
63 
64 

65 
66 
67 
68 
69 

70 
71 
72 
73 
74 

75 

76 

77 
78 
79 

80 
81 
82 
83 
84 

85 
86 

87 
88 
89 

90 
91 
92 
93 
94 

95 
96 
97 
98 
99 

100 



TENTHS OP PER CENT 







1.286456 
1.292354 
1.298291 
1.304267 
1.310282 

1.316334 
1.322425 
1.328554 
1.334722 
1.340928 

1.347174 
1.353456 
1.359778 
1.366139 
1.372536 

1.378971 
1.385446 
1.391956 
1.398505 
1.405091 

1.411715 
1.418374 
1.425072 
1.431807 
1.438579 

1 .445388 
1.452232 
1.459114 
1.466032 
1.472986 

1.479976 
1.487002 
1.494063 
1.501158 
1.508289 

1.515455 
1.522656 
1.529891 
1.537161 
1.544462 

1.551800 



1.287044 
1.292946 
1.298886 
1.304867 
1.310885 

1.316941 
1.323036 
1.329170 
1.335342 
1.341551 

1.347801 
1.354087 
1.360413 
1.366777 
1.373178 

1.379617 
1.386096 
1.392610 
1.399162 
1.405752 

1.412380 
1.419043 
1.425744 
1.432483 
1.439259 

1.446071 
1.452919 
1.459805 
1.466726 
1.473684 

1.480677 
1.487707 
1 .494771 
1.501870 
1.509004 

1.516174 
1.523378 
1.530616 
1.537889 
1.545194 



1.287633 
1.293539 
1.299483 
1.305467 
1.311489 

1.317549 
1.323648 
1.329785 
1.335961 
1.342174 

1.348427 
1.354717 
1.361047 
1.367415 
1.373820 

1.380262 
1.386745 
1.393263 
1.399819 
1.406412 

1.413044 
1.419711 
1.426416 
1.433158 
1.439938 

1.446754 
1.453605 
1.460495 
1.467420 
1.474381 

1.481378 
1.488411 
1.495479 
1.502582 
1.509720 

1.516893 
1.524100 
1.531342 
1 538618 
1.545926 



1.288222 
1.294131 
1.300079 
1.306068 
1.312093 

1.318157 
1.324259 
1.330401 
1.336581 
1.342798 

1.319055 
1.355349 
1.361682 
1.368054 
1.374463 

1.380909 
1.387396 
1.393917 
1.400477 
1 .407074 

1.413709 
1.420380 
1.427089 
1.433835 
1.440619 

1.447438 
1.454292 
1.461186 
1.468115 
1.475080 

1.482080 
1.489117 
1.49G188 
1.503293 
1.510435 

1.517612 
1.524823 
1.532068 
1.539347 
1.546659 



1.288811 
1.294725 
1.300677 
1.306669 
1.312699 

1.318766 
1.324872 
1.331017 
1.337200 
1.343421 

1.349682 
1.355980 
1.362317 
1.368693 
1.375105 

1.381555 
1.388045 
1.394571 
1.401134 
1.407735 

1.414374 
1.421049 
1.427761 
1.434511 
1.441299 

1.448121 
1.454980 
1.461877 
1.468810 
1.475779 

1.482782 
1.4S9S23 
1.496897 
1.504006 
1.511151 

1.518332 
1.525546 
1.532794 
1.540076 
1.547392 



1.289401 
1.295318 
1.301274 
1.307271 
1.313304 

1.319374 
1.325484 
1.331633 
1.337821 
1.344046 

1.350311 
1.358612 
1.362953 
1.369333 
1.375749 

1.382203 
1.388696 
1.395221 
1.401793 
1.408398 

1.415040 
1.421719 
1.428435 
1.435188 
1.441980 

1 

1 455668 
1.462568 
1.469504 
1.476477 

1.483484 
1.490528 
1.497606 
1.504719 
1.511868 

1.519051 
1.526269 
1.533521 
1.540806 
1.548127 



1.289991 
1.295911 
1.301871 
1.307872 
1.313909 

1.319983 
1.326097 
1.332250 
1.338441 
1.344671 

1.350939 
1.357245 
1.363590 
1.369973 
1.376392 

1.382851 
1.389347 
1.395881 
1.402452 
1.409061 

1.415706 
1 .422390 
1.429109 
1.435866 
1.442661 

1.449491 
1.456357 
1.463260 
1 470200 
1.477176 

1.484187 
1.491234 
1.498316 
1.505432 
1.512585 

1.519771 
1.526993 
1.534248 
1.541536 
1.548861 



1.290581 
1.296506 
1.302470 
1.308475 
1.314515 

1.320593 
1.326711 
1.332868 
1.3.39063 
1.345296 

1.351568 
1.357877 
1.364226 
1.370613 
1.377036 

1.383499 
1.389999 
1.396536 
1.403111 
1.409723 

1.416373 
1.423059 
1.429782 
1.4.36543 
1.443342 

1.450175 
1 .457045 
1.463953 
1.470896 
1.477876 

1.484890 
1.491941 
1.499026 
1.506146 
1.513302 

1.520492 
1.527717 
1.534976 
1.542267 
1.549595 



1.291172 
1.297100 
1.303068 
1.309077 
1.315121 

1.321203 
1.327325 
1.333485 
1.339684 
1.345922 

1.352197 
1.358511 
1.364864 
1.371254 
1.377680 

1.384148 
1.390651 
1.397192 
1.403771 
1.410387 

1.417039 
1.423730 
1.430457 
1.437222 
1.444024 

1.450860 
1.457735 
1.464645 
1.471592 
1.478575 

1.485593 
1.492647 
1.499736 
1.506859 
1.514019 

1.521212 
1.528441 
1.535704 
1.542998 
1.550329 



1.291763 
1.297696 
1.303668 
1.309680 
1.315728 

1.321814 
1.327040 
1.334103 
1.340306 
1.346547 

1.352827 
1.359144 
1.365501 
1.371894 
1.378326 

1.384795 
1.391303 
1.397848 
1.404430 
1.411051 

1.417707 
1.424400 
1.431131 
1.437900 
1.444705 

1.451.545 
1.458424 
1.465338 
1.472289 
1.479275 

1 .486297 
1 .493355 
1.500447 
1.507574 
1.514737 

1.521934 
1.529166 
1.536432 
1.543730 
1.551064 



10 



REFRACTOMETER METHOD— TENTA TIVE. 



Determine the refractive index of the solution at 28°C. and obtain the corre- 
sponding percentage of dry substance from 11. If the refractive index is obtained 
at a temperature other than 28°C., correct the result as indicated in 12. If the 
solution is too dark to be read in the instrument, dilute with a concentrated sugar 
solution. Water should never be used for this purpose. Mix weighed amounts 
of the solution under examination and a solution of pure sugar of about the same 
strength, and obtain the amount of dry substance in the former by the following 
formula: 



K] 



SACCHARINE PRODUCTS 



127 



(A + B) C - BD 



in which 



X = per cent of dry substance to be found; 

A = weight in grams of the material mixed with B; 

B = weight in grams of pure sugar solution employed in the dilution; 

C = per cent of dry substance in the mixture of A and B obtained from the 

refractive index; 
D = per cent of dry substance in the pure sugar solution obtained from its 
refractive index. 

11 Table 12.— Geerligs'' Table. 

For dry substance in sugar-house products by the Abbe ref Tactometer, at 28° C. 



INDEX 


PER 
CENT 
DRT 
SUB- 
STANCE 


DECIMALS TO BE 
ADDED FOR 
FRACTIONAL 

READINGS* 


INDEX 


PER 

CENT 
DRT 
SUB- 
STANCE 


DECIMALS TO BE 
A1>DED FOR 
FRACTIONAL 
READIN -S* 


INDEX 


PER 
CENT 
DRT 

SUB- 
STANCE 


DECI.MALS TO BB) 
ADDED FOR 
FRACTIONAL 
BEADINOa* 


1.3335 
1.3349 
1.3364 
1.3379 
1.3394 
1.3409 
1.3424 
1.3439 
1.3454 
1.3469 


1 

2 
3 
4 
5 
6 
7 
8 
9 
10 


0.0001 =0.05 

0002 = 1 
0.0003 = 2 
0001 = 0.25 
0.0005 = 0.3 
000fi= 0.4 
0.0007 = 0.5 
OOOS = 06 
0009 = 0.7 
0.0010 = 75 
0.0011 = 0.8 
0012 = 8 
0013 = 85 
0.0014 = 0.9 
0.0015= 1.0 


1.3484 
1.3500 
1.3516 
1.3530 
1.3546 
1.3562 
1.3578 
1.3594 
1.3611 
1.3627 
1.3644 
1.3661 
1.3678 
1.3695 
1.3712 
1.3729 


11 

12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 


0001 = 0.05 

0002 = 1 
0003 = 2 
0004 = 25 
0.0005 = 3 
0006 = 0.} 
0.0007 = 0.15 
0.000-! = 0.5 
0009 = 0.6 
0.0010 = 0.65 
0.0011 = 7 
0.0012 = 0.75 
0013 = 0.8 
0.0014 = 0.8, 
0015 = 09 
0.0016= 0.95 


1.3746 
1.3764 
1.3782 
1.3800 
1.3818 
1.3836 
1.3854 
1.3872 
1.3890 
1.3909 
1.3928 
1.3947 
1.3966 
1.3984 
1.4003 


27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 


0.0001 =0.05 

0002 = 1 
0.0003 = 0.15 
0004 = 0.2 
0.0005 = 25 
0006 = 0.3 
0007 = 35 
0.0008= 0.4 
0.0009 = 0.45 
0.0010= 0.5 
0.0011 =. 55 
0012 = 06 
0013 = 0.65 
0014 = 07 
,015 = 0.75 
1016=0. 8 
0017 = 85 
0018 = 9 
0019 = 95 
0.0020 = 1 
0.0u21= 1.0 


1.4023 
1.4043 
1.4063 
1.4083 
1.4104 
1.4124 
1.4145 
1.4166 
1.4186 
1.4207 
1.4228 
1.4249 
1.4270 


42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 
53 
54 


0.0 01 = 05 
0002 = 0.1 
0.0003 = 0.15 
0.0004= 2 
0005 = 25 
0006 = 0.3 
0.0007 = 35 
O.O0OS = 4 
0.0009 = 45 
0010= 5 
0011 = 55 
0012 = 0.6 
0.0013 = 65 
0014 = 0.7 
0015 = 75 
0.0016= 0.8 
0.0017 = 0.85 
0018 = 09 
0019 = 0.95 
0020 = 1 
0.0021 = 1.0 


1.4292 
1.4314 
1.4337 
1.4359 
1.43S2 
1.4405 
1.4428 
1.4451 
1.4474 
1.4497 
1.4520 
1.4543 
1.4567 
1.4591 
1.4615 
1.4639 
1.4663 
1.4687 

1 


55 
56 
57 
58 
59 
60 
61 
62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
72 


0.0001 = 0.05 
0002 = 1 
00003 = 1 
0004 =0 15 
0.0005 = 2 
0.0006=0 25 
0.0007 = 3 
0.0008 = 35 
0.0009 = 4 
OOlO = 45 
onii = 05 
0012 = 5 
0.0)13 = 55 
0014 = 6 
0.0015 = 65 
0.0016 = 7 
0017 = 75 
0.0018= 8 
0019 = 85 
0020 = 09 
0021 = 09 
0.0022 = 95 
0023 = 1 
0.0024= 1.0 


1.4711 
1.4736 
1.4761 
1.4786 
1.4811 
1.4836 
1.4862 
1.4888 
1.4914 
1.4940 
1.4966 
1.4992 
1.5019 
1.5046 
1.5073 
1.5100 
1.5127 
1.5155 


73 

74 
75 

76 

77 
78 
79 
80 
81 
• 82 
83 
84 
85 
86 
87 
88 
89 
90 


0001 = 0.0 
0002 = 0.05 
0.0003 = 1 
0004 = 0.15 
0005= 0.2 
0006-0.2 
0.0007 = 25 
0008 - 3 
0009 = 0.35 
0.0010= 35 
00011 = 04 
0.0012 = 45 
0013 = 0.5 
0.0014 = 0.5 
0015 = 55 
0016 = 6 
0.0017 = 65 
0018 = 65 
0019 = 07 
0020 = 0.75 
0021 =08 
0022 = 08 
0023 = 0.85 
00-'4 =09 
0025 = 0.9 
0026 = 95 
0027= 1.0 
0028= 1.0 



*Find in the table the refractive index which is next lower than the reading actu- 
ally made and note the corresponding whole number for the per cent of dry substance 
Subtract the refractive index obtained from the table from the observed reading; 
the decimal corresponding to this difference, as given in the column so marked, is 
added to the whole per cent of dry substance as first obtained. 



128 
12 



methods of analysis 

Table 13. 

Corrections for temperature. 



[Chap, 















DRY SUBSTANCE 










TEMPERA- 
























TURE OF 




























THE 





5 


10 


15 


20 


25 


30 


40 


50 


60 


70 


80 


90 


PRISMS IN 




























"C. 












Subtract 


— 










20 


0.53 


0.54 


0.55 


0.56 


0.57 


0.58 


0.60 


0.62 


0.64 


0.62 


0.61 


0.60 


0.58 


21 


0.46 


0.47 


0.48 


0.49 


0.50 


0.51 


0.52 


0.54 


0.56 


0.54 


0.53 


0.52 


-0.50 


22 


0.40 


0.41 


0.42 


0.42 


0.43 


0.44 


0.45 


0.47 


0.48 


0.47 


0.46 


0.45 


0.44 


23 


0.33 


0.33 


0.34 


0.35 


0.36 


0.37 


0.38 


0.39 


0.40 


0.39 


0.38 


0.38 


0.38 


24 


0.26 


0.26 


0.27 


0.28 


0.28 


0.29 


0.30 


0.31 


0.32 


0.31 


0.31 


0.30 


0.30 


25 


0.20 


0.20 


0.21 


0.21 


0.22 


0.22 


0.23 


0.23 


0.24 


0.23 


0.23 


0.23 


0.22 


26 


0.12 


0.12 


0.13 


0.1^ 


0.14 


0.15 


0.15 


0.16 


0.16 


0.16 


0.15 


0.15 


0.14 


27 


0.07 


0.07 


0.07 


0.07 


0.07 


0.07 


0.08 


0.08 


0.08 


0.08 


0.08 


0.08 


0.07 




Add— 


29 


0.07 


0.07 


0.07 


0.07 


0.07 


0.07 


0.08 


0.08 


0.08 


0.08 


0.08 


0.08 


0.07 


30 


0.12 


0.12 


0.13 


0.14 


0.14 


0.14 


0.15 


0.15 


0.16 


0.16 


0.16 


0.15 


0.14 


31 


0.20 


0.20 


0.21 


0.21 


0.22 


0.22 


0.23 


0.23 


0.24 


0.23 


0.23 


0.23 


0.22 


32 


0.26 


0.26 


0.27 


0.28 


0.28 


0.29 


0.30 


0.31 


0.32 


0.31 


0.31 


0.30 


0.30 


33 


0.33 


0.33 


0.34 


0.35 


0.36 


0.37 


0.38 


0.39 


0.40 


0.39 


0.38 


0.38 


0.38 


34 


0.40 


0.41 


0.42 


0.42 


0.43 


0.44 


0.45 


0.47 


0.48 


0.47 


0.46 


0.45 


0.44 


35 


0.46 


0.47 


0.48 


0.49 


0.50 


0.51 


0.52 


0.54 


0.56 


0.54 


0.53 


0.52 


0.50 



13 



ASH. 

Method I. — Official. 



Heat 5-10 grams of the sample in a 50-100 cc. platinum dish at 100°C. until the 
water is expelled, add a few drops of pure olive oil, and heat slowly over a flame 
until swelling ceases. Then place the dish in a muffle and heat at low redness until 
a white ash is obtained. 



14 



Method 11.— Official. 



Carbonize the mass at a low heat, dissolve the soluble salts in hot water, burn 
the residual mass as directed in 13, add the solution of soluble salts, and evaporate 
to dryness at 100°C., ignite gently, cool in a desiccator, and weigh. 



15 



Method in.— Official. 



Saturate the sample with sulphuric acid, dry, ignite gently, then burn in a muf- 
fle at low redness. Deduct one tenth of the weight of the ash, and calculate the 
per cent. 

1 6 QUANTITATIVE ANALYSIS OF THE ASH.— OFFICIAL. 

Proceed as directed under III. 

1 7 SOLUBLE AND INSOLUBLE ASH.— TENTATIVE. 

Ash the material as directed under 13 or 14. Add water to the ash in the plati- 
num dish, heat nearly to boiling, filter through an ashless filter paper, and wash 
with hot water until the combined filtrate and washings measure about 60 cc. Re 



IX] SACCHARINE PRODUCTS 129 

turn the filter paper and contents to the platinum dish, ignite carefully, and weigh. 
Calculate the percentages of water-soluble and water-insoluble ash. 

1 8 ALKALINITY OF THE SOLUBLE ASH.— TENTATIVE. 

Cool the filtrate from 1 7 and titrate with N/10 hydrochloric acid, using methyl 
orange as an indicator. 

Express the alkalinity in terms of the number of cc. of N/10 acid per 1 gram of 
the sample. 

1 9 ALKALINITY OF THE INSOLUBLE ASH.— TENTATIVE. 

Add an excess of N/10 hydrochloric acid (usually 10-15 cc.) to the ignited insolu- 
ble ash in the platinum dish, under 1 7, heat to boiling over an asbestos plate, cool, 
and titrate the excess of hydrochloric acid with N/10 sodium hydroxid, using methyl 
orange as an indicator. 

Express the alkalinity in terms of the number of cc. of N/10 acid per 1 gram of 
the sample. 

20 MINERAL ADULTERANTS IN THE ASH.— TENTATIVE. 

Mix 100 grams of molasses, sirup, honey, or the confectionery solution prepared 
as directed under 1 (b) and evaporate to a sirupy consistency, with about 35 grams 
of concentrated sulphuric acid in a large porcelain evaporating dish. Pass an 
electric current through it while stirring by placing one platinum electrode in the 
bottom of the dish near one side and attaching the other to the lower end of the 
glass rod with which the contents are stirred. Begin with a current of about 1 
ampere and gradually increase to 4 (modified from method of Budde and Schou* 
for determining nitrogen electrolytically). In 10-15 minutes the mass is reduced 
to a fine dry char, which may be readily burnt to a white ash in the original dish 
over a free flame or in a muffle. 

This method^ is preferred to the ordinary method of heating with sulphuric acid, 
especially in the case of molasses, because, if properly manipulated, it comes quietly 
into the form of a very finely divided char or powder, especially adapted for subse- 
quent quick ignition. 

If an electric current is not available, treat in a large porcelain dish 100 grams of 
the saccharine solution, evaporated to a sirupy consistency, with sufficient concen- 
trated sulphuric acid to thoroughly carbonize the mass and ignite in the usual 
manner. 

The following adulterants may be present: salts of tin, used in molasses to bleach; 
mineral pigments, such as chromate of lead in yellow confectionery; oxid of iron, 
sometimes used to simulate the color of chocolate; and copper. These elements 
may be detected by the usual qualitative tests. 

21 NITROGEN.— TENTATIVE. 

Determine nitrogen in 5 grams of the material as directed under I, 1 8, 21 or 23, 
using a larger quantity of the sulphuric acid if necessary for complete digestion. 

SUCROSE. 

22 Method I.— Tentative. 

(Substances in which the volume of the combined insoluble matter and precipitate 
from clarifying agents is less than 1 cc. from 26 grams.) 

Determine sucrose by polarization before and after inversion, as directed under 

VIII, 14. 



130 METHODS OF ANALYSIS [Chap. 

All products which contain dextrose or other reducing sugars in the crystalline 
form, or in supersaturated solution, exhibit the phenomenon of birotation. The con- 
stant rotation only should be employed in the Clerget formula, and to obtain this 
the solutions prepared for direct polarization should be allowed to stand overnight 
before making the reading. If it is desired to make the direct reading immediately, 
the birotation may be destroyed by heating the neutral solution to boiling for a few 
minutes or by adding a few drops of strong ammonium hydroxid before completing 
the volume. 

23 Method II. (Double dilution method.^) — Tentative. 

(Substances in which the volume- of the combined insoluble matter and 
precipitate from clarifying agents is more than 1 cc. from 26 grams.) 

Weigh out a half normal weight of the sample and make up the solution to 100 
CO., employing the appropriate clarifier (basic lead acetate for dark colored con- 
fectionery or molasses and alumina cream for light colored confectionery). Also 
weigh out a normal weight of the sample and make up a second solution with the 
clarifier to 100 cc. Filter and obtain direct polariscopic readings of both solu- 
tions. Invert each solution as directed in 22 and obtain its invert reading. 

The true direct polarization of the sample is the product of the two direct read- 
ings divided by their difference. 

The true invert polarization is the product of the two invert readings divided 
by their difference. 

Calculate the sucrose from the true polarizations thus obtained by the formula 
given under VIII, 14. 

COMMERCIAL GLUCOSE (APPROXIMATE). 

24 Method I. — Tentative. 

(Substances containing little or no invert sugar.) 

Commercial glucose can not be determined accurately owing to the varying 
amounts of dextrin, maltose, and dextrose present in this product. However, in 
sirups, in which the amount of invert sugar is so small as not to appreciably affect 
the result, commercial glucose may be estimated approximately by the following 
formula:^ 

(a - S) 100 . 

G = in which 

175 

G = per cent of commercial glucose; 

a = direct polarization; 

S = per cent of cane sugar. 

Express the results in terms of commercial glucose polarizing +175°V. 

Method II. — Tentative. 

25 (Substances containing invert sugar. ^) 

Prepare an inverted half normal solution of the substance as directed under 
VIII, 14 except that after inversion cool the solution, make neutral to phenol- 
phthalein with sodium hydroxid solution, slightly acidify with hydrochloric acid, 
and treat with 5-10 cc. of alumina cream before making up to the mark. Filter 
and polarize at 87°C. in a 200 mm. jacketed tube. Multiply the reading by 200 and 
divide by the factor 163 to express the amount of glucose present in terms of glu- 
cose polarizing 4-175°V. 



IX] SACCHARINE PRODUCTS 131 

26 REDUCING SUGARS— TENTATIVE. 

Determine either as dextrose or invert sugar as directed under VIII, 50, 51, 
52, 54, or 21, 23, 25, 36 or 39. 

27 STARCH.— TENTATIVE. 

Measure 25 cc. of a solution or uniform mixture, prepared as directed in 1 (b), 
(representing 5 grams of the sample) into a 300 cc. beaker, or introduce 5 grams of 
the finely ground sample (previously extracted with ether if the sample contains 
much fat) into the beaker, add sufficient water to make the volume 100 cc, heat 
to about 60°C. (avoiding if possible gelatinizing the starch) and allow to stand 
for about an hour, stirring frequently to secure complete solution of the sugars. 
Transfer to a stout wide-mouthed bottle, rinse the beaker with a little warm water, 
cool, add an equal volume of 95% alcohol, mix, and allow to stand at least an hour. 
Centrifugalize until the precipitate is closely packed on the bottom of the bottle 
and decant the supernatant liquid through a hardened filter. Wash the precipi- 
tate with successive 50 cc. portions of 50% alcohol by centrifugalizing and decant- 
ing through the filter until 3 or 4 drops of the washings give no test for sugar with 
alphanaphthol as described under 68. Transfer the residue from the bottle and 
the hardened filter to a large flask and determine starch as directed under VIII, 

60. 

ETHER EXTRACT IN CONFECTIONERY. 

28 Continuous Extraction. — Tentative. 

(1) Measure 25 cc. of a 20% mixture or solution, prepared as directed under 1 
(b), into a very thin, readily frangible, glass evaporating shell {Hofmeister Schalchen), 
containing 5-7 grams of freshly ignited asbestos fiber; or (2) If impossible to ob- 
tain a uniform sample, weigh 5 grams of the mixed finely divided sample into a 
dish, and wash with water upon the asbestos in the evaporating shell, using, if neces- 
sary, a small portion of the asbestos fiber on a stirring rod to transfer the last traces 
of the sample from the dish to the shell. Dry to constant weight at 100°C., cool, 
wrap loosely in smooth paper, crush into rather small fragments between the fin- 
gers, transfer carefully the crushed mass, exclusive of the paper, to an extraction 
tube or a fat extraction cartridge. A thin lead disk (bottle cap) may be substituted 
for the Schalchen. The disk may then be cut into small pieces and placed in the 
extraction tube. Extract with anhydrous ether or petroleum ether (b. p. 45°-60°C. 
and without weighable residue) in a continuous extraction apparatus for at least 25 
hours. In most cases it is advisable to remove the substance from the extractor 
after the first 12 hours, grind with sand to a fine powder, and re-extract for the re- 
maining 13 hours. Transfer the extract to a tared flask, evaporate the solvent, dry 
to constant weight in an oven at 100°C. 

29 Roese-Gottlieb Method. — Tentative. 

Substances such as butter-scotch, invariably yield extremely inaccurate results 
by the above method. In such cases introduce 4 grams of the material, or an amount 
of a uniform solution equivalent to this amount of the dry substance, into a Rohrig 
tube or similar apparatus, make up to a volume of 10 cc. with water, add 1.25 cc. 
of concentrated ammonium hydroxid and mix thoroughly. Add 10 cc. of 95% alco- 
hol and mix. Then add 25 cc. of washed ether and shake vigorously for half a min- 
ute; then add 25 cc. of petroleum ether (b. p. below 60°C.), and shake again for 
half a minute. Allow to stand for 20 minutes or until the separation between the 



132 METHODS OF ANALYSIS [Chap. 

liquids is complete. Draw off as much as possible of the ether-fat solution (usually 
0.5-0.8 cc. will be left) into a weighed flask through a small, rapid filter. The flask 
should be weighed with a similar one as a counterpoise. Again extract the liquid 
remaining in the tube, this time with 15 cc. each of ether and petroleum ether, shake 
vigorously half a minute with each, and allow to settle. Proceed as above, wash- 
ing the tip of the spigot and the filter with a few cc. of a mixture of equal parts of 
the 2 ethers (previously mixed and free from deposited water). For absolutely 
exact results the extraction must be repeated. This third extraction usually yields 
not more than about 1 mg. of fat, if the previous ether-fat solutions have been 
drawn off closely, or an amount averaging about 0.02% on a 4 gram charge. Evapo- 
rate the ether slowly on a steam bath, then dry the fat in a boiling water oven until 
the loss in weight ceases. Test the purity of the fat by dissolving in a little petro- 
leum ether. Should a residue remain, wash the fat out completely with petroleum 
ether, dry the residue, weigh, and deduct the weight. 

30 PARAFFIN IN CONFECTIONERY.— TENTATIVE. 

Add to the ether extract in the flask, as above obtained, 10 cc. of 95% alcohol 
and 2 cc. of sodium hydroxid solution (1 to 1), connect the flask with a reflux con- 
denser, and heat for an hour on the water bath, or until saponification is complete. 
Remove the condenser and allow the flask to remain on the bath until the alcohol 
is evaporated and the residue is dry. Dissolve the residue as completely as pos- 
sible in about 40 cc. of water and heat on the bath, shaking frequently. Wash into 
a separatory funnel, cool, and extract with 4 successive portions of petroleum ether, 
which are collected in a tared flask or capsule. Evaporate the petroleum ether 
and dry in the oven to constant weight. 

Any phytosterol or cholesterol present in the fat would be extracted with the 
parafiin. The amount is so insignificant that it may be disregarded generally. 
The character of the final residue should, however, be confirmed by determining 
its melting point, specific gravity, and refractive index. 

31 ALCOHOL IN SIRUPS USED IN CONFECTIONERY ("BRANDY DROPS").— TENTATIVE. 

Collect in a beaker the sirup from a sufficient number of pieces to yield 30-50 
grams of sirup. Strain the sirup into a tared beaker and weigh. Introduce the 
sirup into a 250-300 cc. distilling flask, dilute with half its volume of water, attach 
the flask to a vertical condenser and distil almost 50 cc, or as much of the liquid as 
possible without causing charring. Foaming may be prevented by adding a little 
tannin, or a piece of paraffin about the size of a pea, to the contents of the distil- 
lation flask. Cool the distillate, make up to volume with water, mix well, and 
ascertain the specific gravity of the liquid by means of a pycnometer, and obtain 
the corresponding weight of alcohol in the 50 cc. of distillate from XVI, 5. Cal- 
culate the per cent by weight of alcohol in the candy filling. 

32 COLORING MATTER.— TENTATIVE. 
Proceed as directed under XI. 

33 METALS.— TENTATIVE. 
Proceed as directed under XII. 



IX] SACCHARINE PRODUCTS 133 

HONEY. 8 

34 PREPARATION OF SAMPLE.— TENTATIVE, 

(a) Liquid or strained honey. — If the sample is free from granulation, mix thor- 
oughly by stirring or shaking before drawing weighed portions for the analytical 
determination. If the honey is granulated, place the container, having the stopper 
loose, in a water bath, and heat at a temperature not exceeding 50°C. until the sugar 
crystals dissolve; mix thoroughly, cool, and weigh portions for the analytical de- 
terminations. If sediment such as particles of comb, wax, sticks, bees, etc., are 
present, heat the sample to 40°C. in a water bath and filter through cheese-cloth 
before weighing portions for analysis. 

(b) Comh honey. — Cut across the top of the comb, if sealed, and separate com- 
pletely from the comb by straining through a 40 mesh sieve. When portions of the 
comb or wax pass through the sieve, heat the sample as in (a) and strain through 
cloth. If the honey is granulated in the comb, heat until the wax is liquified, stir, 
cool, remove the wax and take the clear liquid for analysis. 

35 MOISTURE. 

Weigh 2 grams of the sample into a tared, flat-bottomed aluminium dish, having a 
diameter of about 60 mm. and containing 10-15 grams of fine quartz sand, which has 
been previously washed, dried and ignited, and a small glass stirring rod; add 5-10 
cc. of water and thoroughly incorporate with the sand and honey mixture by means 
of the rod; dry the dish and its contents to constant weight in a vacuum oven at 
a temperature not exceeding 70°C. 

36 ASH.— OFFICIAL. 

Weigh 5-10 grams of honey into a platinum dish, add a few drops of pure olive 
oil to prevent spattering, and heat carefully until swelling ceases and then ignite 
at a temperature not above dull redness until a white ash is obtained. 

37 SOLUBLE ASH.— TENTATIVE. 
Proceed as directed under 17. 

38 ALKALINITY OF THE SOLUBLE ASH.— TENTATIVE. 

Proceed as directed under 18. 

POLARIZATION. 

39 Direct Polarization. — Tentative. 

(a) Immediate direct -polarization. — Transfer 26 grams of the honey to a 100 
cc. flask with water, add 5 cc. of alumina cream, dilute to the mark with water at 
20°C., filter, and polarize immediately in a 200 mm. tube. 

(b) Constant direct polarization. — Pour the solution from the tube used in read- 
ing (a) back into the flask, stopper, and allow to stand for 24 hours. At the end of 
this time again polarize the solution at 20°C. in a 200 mm. tube. 

(C) Birotation. — The difference between (a) and (b) gives the birotation. 
(d) Direct polarization at 87°C. — Polarize the solution, obtained in (b), at 87°C. 
in a jacketed 200 mm. tube. 



134 METHODS OF ANALYSIS [Chap. 

40 Invert Polarization. — Tentative. 

(a) At 20°C. — Invert 50 cc. of the solution obtained in 39 as directed under 
VIII, 14 or 16, and polarize at 20°C. in a 200 mm. tube. 

(b) At 87°C. — Polarize the solution, obtained as directed in (a), at 87°C. in a 200 
mm. jacketed tube. 

41 REDUCING SUGARS.— TENTATIVE. 

Dilute 10 cc. of the solution, used for direct polarization, 39, to 250 cc. and de- 
termine reducing sugars in 25 cc. of this solution by one of the methods given under 
VIII, 25, 36, 39 or 56, respectively. Calculate the result to per cent of invert 
sugar. 

42 SUCROSE.— TENTATIVE. 

Proceed as directed under VIII, 18. Determine reducing sugars after inver- 
sion by diluting 10 cc. of the solution obtained in 40, with a small amount of water, 
neutralizing with sodium carbonate, and making up to 250 cc. with water. Employ 
50 cc. of this solution for the determination, using the same method as in 41 . 

43 LEVULOSE.— TENTATIVE. 

Multiply the direct reading at 87°C., 39 (d), by 1.0315 and subtract the product 
from the constant direct polarization at 20°C., 39 (b): divide the difference by 2.3919 
to obtain the grams of levulose in a normal weight of the honey. From this figure 
calculate the per cent of levulose in the original sample. 

44 DEXTROSE.— TENTATIVE. 

Subtract the per cent of levulose, obtained in 43, from the per cent of invert 
sugar, found in 41 , to obtain the approximate per cent of dextrose. 

The dextrose can be determined more accurately by multiplying the per cent 
of levulose, as found in 43, by the factor 0.915, which gives its dextrose equivalent 
in copper reducing power. Subtract this figure from that of the reducing sugars, 41 , 
calculated as dextrose, to obtain the percentage of dextrose in the sample. (Owing 
to the difference in the reducing powers of different sugars, the sum of the dex- 
trose thus found and the levulose as obtained in 43 will be greater than the amount 
of invert sugar obtained in 41). 

45 DEXTRIN (APPROXIMATE).— TENTATIVE. 

Transfer 8 grams of the sample (4 grams in the case of dark colored honey-dew 
honey) to a 100 cc. flask (using not more than 4 cc. of water) by allowing the sam- 
ple to drain from the weighing dish into the flask and then dissolving the residue in 
2 cc. of water. After adding this solution to the contents of the flask, rinse the 
weighing dish with two 1 cc. portions of water to which a little alcohol is added sub- 
sequently. Fill the flask to the mark with absolute alcohol, shaking constantly. 
Set the flask aside until the dextrin has collected on the sides and bottom and the 
liquid is clear. Decant the clear liquid through a filter paper and wash the resi- 
due in the flask with 10 cc. of 95% alcohol, pouring the washings through the same 
filter. Dissolve the dextrin in the flask with boiling water and filter through the 
filter paper already used, receiving the filtrate in a tared dish, prepared as directed 
under 4. Rinse the flask and wash the filter a number of times with small portions 
of hot water, evaporate on a water bath and dry to constant weight in vacuo 
at 70°C. 



IXJ SACCHARINE PRODUCTS 135 

After determining the weight of the alcohol precipitate, dissolve the latter in 
water and make up to definite volume, using 50 cc. of water for each 0.5 gram of pre- 
cipitate or part thereof. 

Determine reducing sugars in the solution both before and after inversion as 
directed under VIII, 18, expressing the results as invert sugar. Calculate sucrose 
from the results thus obtained and subtract the sum of the reducing sugars before 
inversion and sucrose from the weight of the total alcoholic precipitate to obtain 
the weight of the dextrin. 

46 FREE ACID.— TENTATIVE. 

Dissolve 10 grams of the honey in water and titrate with N/10 sodium hydroxid 
using phenolphthalein as an indicator. Express the results in terms of cc.of N/10 
sodium hydroxid required to neutralize 100 grams of the sample. 

47 GLUCOSE.— TENTATIVE. 

Qualitative test. — Dilute the honey with water in the proportion of 1 to 1, then add 
a tew cc. of iodin solution (1 gram of iodin, 3 grams of potassium iodid, 50 cc. of 
water). In the presence of glucose the solution turns red or violet, the depth and 
character of the color depending upon the quality and nature of the glucose em- 
ployed. A blank test with a pure honey of about the same color should be made 
in order to secure an accurate color comparison. Should the honey be dark and 
the percentage of glucose very small, precipitate the dextrin which may be pres- 
ent by adding several volumes of 95% alcohol. Allow to stand until the precipitate 
settles (do not filter), decant the liquid, dissolve the residue of dextrins in hot 
water, cool and apply the above test to this solution. A negative result is not 
proof of the absence of glucose as some glucose, especially of high conversion, does 
not give any reaction with iodin.' 

Quantitative test. — An approximate determination can be made by Browne's 
formula as follows: Multiply the difference in the polarizations of the invert solu- 
tion at 20°C. and 87°C. by 77 and divide this product by the percentage of invert 
sugar after inversion found in the sample. Multiply the quotient by 100 and di- 
vide the product by 26.7, to obtain the percentage of honey in the sample; 100 per 
cent minus the per cent of honey gives the percentage of glucose. 

COMMERCIAL INVERT SUGAR." 

QUALITATIVE TESTS. 

Fiehe Test {Bryan Modification^^). — Tentative. 

48 REAGENT. 

Resorcin solution. — Dissolve 1 gram of resorcin in 100 cc. of hydrochloric acid, 
sp. gr. 1.19. 



49 



MANIPULATION. 



Introduce 10 cc. of a 50% honey solution into a test tube and add 5 cc. of ether. 
Shake gently and allow to stand for some time until the ether layer is clear. Trans- 
fer 2 cc. of this clear ether solution to a small test tube and add a large drop of the 
resorcin solution. Shake and note the color immediately. In the presence of arti- 
ficial invert sugar, the resorcin assumes immediately an orange-red color turning 
to dark red. 



136 METHODS OF ANALYSIS [Chap. 

Feder Anilin Chlorid Test.^^ — Tentative. 

50 REAGENT. 

Anilin chlorid solution. — To 100 cc. of C. P. anilin add 30 cc. of 25% hydrochloric 
acid. 

51 MANIPULATION. 

Introduce 5 grams of the honey into a porcelain dish and add 2.5 cc. of the anilin 
reagent. A bright red color indicates the presence of commercial invert sugar. 

52 DIASTASE." 

Mix 1 part of honey with 2 parts of sterile water. Treat 10 cc. of this solution 
with 1 cc. of 1% soluble starch solution and digest at 45°C. for an hour. At the end 
of this time test the mixture with 1 cc. of iodin solution (1 gram of iodin, 2 grams 
of potassium iodid, 300 cc. of water). Treat another 10 cc. portion of the honey 
solution, mixed with 1 cc. of the soluble starch solution, without heating to 45°C., 
with the reagent and compare the colors produced. If the original honey had not 
been heated suiBciently to kill the diastase, an olive-green or brown coloration will 
be produced in the mixture that has been heated at 45°C. Heated or artificial 
honey becomes blue. 

MAPLE PRODUCTS. 

53 PREPARATION OF SAMPLE.— TENTATIVE. 

(a) Maple sirup. — Determine the moisture by the method given under 54 (a). If 
the moisture is less than 35%, and there is some mineral sediment, pour the clear 
sirup into a beaker, washing the sediment also into the beaker with water. Then 
concentrate the sirup by boiling to a moisture content of about 35% (b. p. 104°C.). 
Set aside until cool, or preferably let the covered material stand overnight, and 
pour off the clear liquid for the analytical work. Where no sediment is present 
the sample is ready for analysis after careful mixing. Where sugar has crystal- 
lized out, warm to dissolve the sugar before starting the analysis. It is desira- 
ble in order to compare results upon different samples, to reduce all results other 
than moisture to a dry substance basis as determined in the clear sirup. 

(b) Maple sugar, maple cream, maple wax, etc. — Determine moisture, by the meth- 
od given under 54 (b), in the sample in its original condition by thoroughly mixing, 
if semi-plastic, or by rubbing up in a mortar representative portions of the product 
if solid. For all other analytical determinations use a solution prepared as fol- 
lows: Weigh roughly 100 grams of the product into a beaker and dissolve by boil- 
ing with 200 cc. of water. Decant the resulting sirup while hot through a muslin 
filter, concentrate by boiling to a moisture content of 35% (b. p. 104°C.), cool, or 
preferably let the covered material stand overnight, set aside until clear, and use 
this clear sirup for analysis. It is desirable, in order to compare results upon 
different samples, that all results except moisture be expressed upon a dry basis. 

54 MOISTURE.— TENTATIVE. 

(a) Maple sirup. — Proceed as directed under 35 or 10. 

(b) Maple sugar, maple cream, etc. — Proceed as directed under 35. 

55 POLARIZATION.— TENTATIVE. 

(a) Direct at ;?0°C.— Proceed as directed under VIII, 14. 

(b) Invert at ^0°C.— Proceed as directed under VIII, 14. 

(C) Invert at 87°C. — Proceed as directed under 25 to detect commercial glucose. 



IX] SACCHARINE PRODUCTS 137 

56 REDUCING SUGARS AS INVERT SUGAR.— TENTATIVE. 

(a) Before inversion. — Proceed as directed under VIII, 25, using an aliquot of 
the solution used for direct polarization, 55 (a), and only neutral lead acetate for 
clarification. 

(b) After inversion. — Proceed as directed under VIII, 25, using an aliquot of 
the solution used for the invert polarization, 55 (b), and only neutral lead acetate 
for clarification. 

SUCROSE. 

57 By Polarization. — Tentative. 
Proceed as directed under VIII, 14 or 16. 

58 By Reducing Sugars Before and After Inversion. — Tentative. 
Proceed as directed under VIII, 18. 

59 TOTAL ASH.— TENTATIVE. 
Proceed as directed under 13. 

60 SOLUBLE AND INSOLUBLE ASH.— TENTATIVE. 
Proceed as directed under 17. 

61 ALKALINITY OF THE SOLUBLE ASH.— TENTATIVE. 
Proceed as directed under 18. 

62 ALKALINITY OF THE INSOLUBLE ASH.— TENTATIVE. 
Proceed as directed under 19. 

LEAD NUMBER (WINTON).— TENTATIVE. 

63 REAGENTS. 

Standard basic lead acetate solution. — Boil 430 grams of normal lead acetate and 
130 grams of litharge, for 30 minutes, or boil 560 grams of Home's dry basic lead 
acetate with 1 liter of water, cool, allow to settle and dilute the supernatant liquid 
to 1.25 sp. gr. To a measured amount of this solution add 4 volumes of water and 
filter if not perfectly clear. The solution should be standardized each time a set 
of determinations is made. 

If the directions for preparing the basic lead acetate are not carried out care- 
fully, the use of Home's dry basic lead acetate is preferable. 



64 



DETERMINATION OF LEAD IN THE BLANK. 



Transfer 25 cc. of the standard basic lead acetate to a 100 cc. flask, add a few drops 
of acetic acid, and make up to the mark with water. Shake and determine lead 
sulphate in 10 cc. of the solution as directed under 65. The use of the acid is im- 
perative in this case to keep the lead in solution, when diluted with water. 



65 



DETERMINATION. 



Transfer 25 grams of the sample to a 100 cc. flask by means of water. Add 25 
cc. of the standard basic lead acetate and shake, fill to the mark, shake, and allow to 
stand for at least 3 hours before filtering. Pipette 10 cc. of the clear filtrate into 
a 250 cc. beaker, add 40 cc. of water and 1 cc. of concentrated sulphuric acid, shake 
and add 100 cc. of 95% alcohol. Allow to stand overnight, filter on a tared Gooch, 



138 METHODS OF ANALYSIS [Chap. 

wash with 95% alcohol, dry in a water oven, and ignite in a muffle or over a Bun- 
sen burner, applying the heat gradually at first, and avoiding a reducing flame. 
Cool and weigh. Subtract the weight of lead sulphate so found from the weight of 
lead sulphate found in the blank, 64, and multiply by the factor 27.325. The use 
of this factor gives the lead number directly without the various calculations other- 
wise required. 

MALIC-ACID VALUE. 

66 Cowles Method.^* — Tentative. 

Weigh 6.7 grams of the sample into a 200 cc. beaker, add 5 cc. of water, then 2 
cc. of a 10% calcium acetate solution and stir. Add gradually, and with constant 
stirring, 100 cc. of 95% alcohol, and agitate the solution until the precipitate set- 
tles, or let stand, until the supernatant liquid is clear. Filter off the precipitate 
and wash with 75 cc. of 85% alcohol. Dry the filter paper and ignite in a platinum 
dish. Add 10 cc. of N/10 hydrochloric acid and warm gently until all the lime 
dissolves. Cool and titrate back with N/10 sodium hydroxid, using methyl orange 
as an indicator. The difference in cc. divided by 10 represents the malic acid value 
of the sample. Previous to use the reagents should be tested by a blank determina- 
tion and any necessary corrections applied. 

67 METALS.— TENTATIVE. 

Proceed as directed under XII. 

SUGAR HOUSE PRODUCTS. 
SUCROSE IN BEETS. 

68 Alcohol Extraction Method {Herzfeld Modification^^). — Tentative. 

Weigh 26 grams of the beet pulp and transfer to a 100 cc. flask with about 50 cc. 
of 90% alcohol and 3-5 cc. of basic lead acetate solution. Connect a reflux condenser 
to the flask and place on a boiling water bath for 10-15 minutes. Then pour the 
whole into a Soxhlet extractor, washing out the flask with fresh portions of 90% 
alcohol. Connect the same 100 cc. flask to the extractor, and fit the latter with 
a return condenser. Add 90% alcohol until the siphon is started and the flask is 
about three fourths full. Place the flask in a covered water bath kept at a heat 
that will allow the alcohol to boil freely. Continue the extraction for 1-4 hours, 
or until a test of the alcohol in the extractor gives no color withalpha-naphthol 
solution when tested as follows: Introduce into a test tube a few drops of the alco- 
hol coming from the extractor, add 4 or 5 drops of a 20% alcoholic alpha-naphthol 
solution and 2 cc. of water. Shake well, tip the tube, and allow 2-5 cc. of colorless 
concentrated sulphuric acid to flow down the side of the tube; then hold the tube 
upright and, if sucrose is present, a color varying from a faint to a deep violet will 
be noted at the junction of the two liquids. On shaking, the whole solution becomes 
a blue violet color. This test is suitable for this work, but it must be remembered 
that other substances besides sucrose give this color reaction. 

Remove the flask, transfer to a 100 cc. graduated flask, cool to the standard 
temperature, dilute to the mark with 90% alcohol, shake and filter, keeping the 
funnel covered with a watch glass. Polarize in a 200 mm. tube. 

Avoid evaporation and changes of temperature and also use a minimum amount 
of basic acetate for clarification, 3 cc. rather than 5 cc. By digesting; the beet 
pulp with the alcohol before extraction, the time of extraction is greitly shortened 
the pulp becomes thoroughly impregnated with the alcohol, and all the air is re- 
moved, resulting in a good extraction of the whole material. If the pulp is fine 



IX] SACCHARINE PRODUCTS 139 

and tends to clog the siphon, alcohol-washed cotton may be used as a plug in the 
extractor before adding the beet pulp, and a fine mesh screen may be placed over 
the pulp to keep the whole compact in the extractor. 

69 Pellet Aqueous Method}^ {Hot Digestion). — Tentative. 

Weigh 52 grams of the beet cuttings and transfer them with water to a wide- 
mouthed flask graduated to a content of 201.2 cc; add 5-10 cc. of basic lead acetate 
solution, fill the flask to the mark with hot water, and shake. Immerse the flask 
in a water bath at 80°C. and rotate at intervals. Add water from time to time so 
that at the end of the heating (about 30 minutes) the water in the flask is a little 
above the mark. Remove the flask from the water bath and allow it to cool to 
standard temperature. Add sufiicient concentrated acetic acid to make the solu- 
tion very slightly acid (generally less than 0.5 cc.) and a few drops of ether to break 
the foam. Make up to the mark, mix thoroughly, filter, and polarize in a 200 mm. 
tube. 

The fineness of the pulp governs the time of heating. Add enough water at the 
start and maintain this volume during the extraction, so that not more than 5 cc. of 
water will be necessary to complete the volume after cooling. The proportion of 
pulp to water must not be increased beyond the prescribed amount, for when smaller 
proportions of water to pulp are used and then a large quantity of water is added at 
the last to make up to volume, the sugar does not become equally diffused and the 
results are too low. Differences of over 1% in sugar content may be caused by lack 
of care in this particular. 

70 Hot Water Digestion Method. — Tentative. 
(Herzfeld Modification of the Sachs Le Docte Method*^.) 

There are needed nickel-plated sheet iron vessels, 11 cm. high, 6 cm. body diame- 
ter, and 4 cm. mouth diameter, also stoppers covered with tin foil to fit the same. 

Weigh 26 grams of the beet pulp on a watch glass (small enough to go into the 
neck of the beaker) and transfer to the metal beaker, add 177 cc. of dilute basic 
lead acetate solution (5 parts of basic lead acetate solution (sp. gr. 1.25) to 100 
parts of water), shake and stopper lightly. Submerge the beaker in a water bath 
at 75°-80°C. for 30 minutes, shaking intermittently. When all the air has been 
expelled (generally after 5 minutes), tighten the stopper. After 30 minutes, shake, 
cool to standard temperature, filter, add a drop of acetic acid to the filtrate and 
polarize in a 400 mm. tube. The reading is the per cent of sugar in the beet pulp. 

BIBLIOGRAPHY. 

1 Browne. Handbook of Sugar Analysis. 1912, p. 16. 

2 Wiss. Abh. der Kaiserlichen Normal-Eichungs-Kommission, 1900, 2: 153; U. S. 
Bur. Standards, Circ. 19, 5th ed., p. 26. 

3 Intern. Sugar J., 10: 69; U. S. Bur. Chem. Bull. 122, p. 169. 

* Z. anal. Chem., 1899, 38: 345. 

* Leach. Food Inspection and Analysis. 1913, p. 624. 
« Analyst, 1896, 21: 182. 

^ Leach. Food Inspection and Analysis. 1913, p. 622. 

8 U. S. Bur. Chem. Bulls. 110 and 154; Z. Nahr. Genussm., 1909, 18: 625. 

9 U. S. Bur. Chem. Bull. 110, p. 60. 
1° Ibid., 110 and 154. 

" Ibid., 154, p. 15. 

12 Analyst, 1911, 36: 586. 

13 Z. Nahr. Genussm., 1910, 19: 72. 

1* J. Am. Chem. Soc, 1908, 30: 1285. 
16 U. S. Bur. Chem. Bull. 146, p. 17. 
i« Ibid., p. 18. 
1' Ibid., p. 19. 



X. FOOD PRESERVATIVES.— TENTATIVE. 
SALICYLIC ACID. 

1 PREPARATION OF SAMPLE. 

(a) Non-alcoholic liquids. — Many liquids may be extracted directly as described 
in 2 or 4 without further treatment. If gums or mucilaginous substances are present, 
pipette 100 cc. into a 250 cc. volumetric flask, add about 5 grams of sodium chlorid, 
shake until the latter is dissolved, make up to the mark with alcohol, shake vigor- 
ously, allow the mixture to stand for 10 minutes with occasional shaking, filter 
through a dry folded filter and treat an aliquot of the filtrate as directed under (b). 

(b) Alcoholic liquids. — Make 200 cc. of the sample alkaline with sodium hydroxid 
solution, using litmus as an indicator, and evaporate on a steam bath to about one 
third its original volume. Dilute to the original volume with water and filter, if 
necessary, through a dry filter. 

(C) Solid or semi-solid substances. — Grind the sample and mix thoroughly. Trans- 
fer a convenient quantity (50-200 grams according to the consistency of the sam- 
ple) to a 500 cc. volumetric flask, add suflScient water to make a volume of about 
400 cc, shake until the mixture becomes uniform, add 2-5 grams of calcium chlorid, 
shake until the latter is dissolved, render distinctly alkaline with sodium hydroxid 
solution, using litmus as an indicator, fill to the mark with water, shake thoroughly, 
allow to stand for at least 2 hours shaking frequently and filter through a large 
folded filter. 

DETECTION AND ESTIMATION. 

2 Ferric Chlorid Test. — Qualitative. 

Introduce 50 cc. of the sample or an equivalent amount of an aqueous extract, 
prepared as directed under 1, into a separatory funnel, add one tenth its volume 
of dilute hydrochloric acid (1 to 3) and extract with 50 cc. of ether. If the mixture 
emulsifies, add 10-15 cc. of petroleum ether (b. p. below 60°C.) and shake. If this 
treatment fails to break the emulsion whirl the mixture in a centrifuge, or allow it 
to stand until a considerable portion of the aqueous layer has separated, run o£f 
the latter, shake vigorously and again allow to separate. Wash the ether layer 
with two 5 cc. portions of water, evaporate the greater portion of the ether in a por- 
celain dish on a steam bath, allow the remainder to evaporate spontaneously and 
add a drop of 0.5% ferric chlorid solution. A violet color indicates salicylic acid. 

If coloring matter or other interfering substances are present in the residue 
left after evaporation of the ether, purify the salicylic acid by one of the following 
methods: 

(a) Dissolve the residue from the ether extract, obtained as directed above, 
in about 25 cc. of ether, transfer the latter to a separatory funnel and shake with 
an equal quantity of water, made distinctly alkaline with several drops of am- 
monium hydroxid. Allow to separate, filter the aqueous layer through a wet fil- 
ter into a porcelain dish, evaporate almost to dryness, and test the residue as directed 
above. 

(b) Dry the residue from the ether extract, obtained as directed above, in a 
desiccator over sulphuric acid and extract with several 10 cc. portions of carbon 

141 



142 METHODS OF ANALYSIS [Chap, 

disulphid or petroleum ether (b. p. below 60°C.), rubbing the contents of the dish 
with a glass rod, and filtering the successive portions of the solvent through a dry 
paper into a second porcelain dish. Evaporate the greater portion of the solvent 
on a steam bath, allow the remainder to evaporate spontaneously and test the 
residue as directed above. 

(C) Transfer the residue from the ether extract, obtained as directed above, 
to a small porcelain crucible by means of a few cc. of ether and allow the solvent 
to evaporate spontaneously. Cut a hole in a piece of asbestos board sufficiently 
large to admit about two thirds of the crucible, cover the latter with a small, round- 
bottomed flask filled with cold water, and heat over a small Bunsen flame until 
any salicylic acid present has sublimed and condensed upon the bottom of the 
fiask. Test the sublimate as directed above. 

3 Jorissen's Test.^ — Qualitative. 

Dissolve the residue from the ether extract, obtained as directed under 2, or, 
in case impurities are present, the purified material obtained as directed under 2 
(a), (b)or (C) in a little hot water. Cool 10 cc. of the solution in a test tube, add 

4 or 5 drops of 10% potassium nitrite solution, 4 or 5 drops of 50% acetic acid and 
1 drop of 10% cupric sulphate solution, mix thoroughly and heat to boiling. Boil 
for half a minute and allow to stand for 1-2 minutes. In the presence of salicylic 
acid a blood red color will develop. 

Colorimetric Method. — Quantitative. 

4 EXTRACTION. 

Pipette a convenient portion of the sample (100 cc. or a volume representing not 
less than 20 grams of the original sample) or a solution, prepared as in 1 , into a sepa- 
ratory funnel, make the solution neutral to litmus with dilute hydrochloric acid 
(1 to 3) and add an excess of concentrated hydrochloric acid equivalent to 2 cc. 
of acid for each 100 cc. of solution. Extract with 4 separate portions of ether, 
using for each extraction a volume of ether equivalent to half the volume of the 
aqueous layer. If an emulsion forms on shaking, this may usually be broken by 
adding a little (one fifth the volume of the ether layer) petroleum ether (b. p. be- 
low 60°C.) and shaking again or by centrifugalizing. If an emulsion still persists, 
allow it to remain with the aqueous layer. If an emulsion remains after the 
fourth extraction, separate it from the clear ether and the clear aqueous layer 
and extract it separately with 2-3 small portions of ether. Combine the ether 
extracts, wash with one tenth their volume of water, allow the layers to separate 
and reject the aqueous layer. Wash in this way until the aqueous layer after sepa- 
ration yields a yellow color upon the addition of methyl orange and 2 drops of N/10 
sodium hydroxid. Distil slowly the greater part of the ether, transfer the remainder 
to a porcelain dish and allow the ether to evaporate spontaneously. If there are 
no interfering substances present, proceed as directed in 5. If such interfering 
substances are present, purify the residue by one of the following methods: 

(a) Dry thoroughly the residue in vacuo over sulphuric acid and extract with 
10 portions of 10-15 cc. each of carbon disulphid or petroleum ether (b. p. below 
60°C.), rub the contents of the dish with a glass rod and filter the successive portions 
of the solvent through a dry filter into a porcelain dish. Test the extracted resi- 
due with a drop of ferric alum solution and, if it gives a reaction for salicylic acid, 
dissolve it in water and reextract with ether, proceeding as directed above. Dis- 
til the greater portion of the carbon disulphid or petroleum ether and allow the 
remainder to evaporate spontaneously. Proceed as directed in 5. 



X] FOOD PRESERVATIVES 143 

(b) Dissolve the residue in 40-50 cc. of ether. Transfer the ether solution to 
a separatory funnel and extract with 3 successive 15 cc. portions of 1% ammonium 
hydroxid. (If fat is known to be present in the original ether extract, extract the 
latter directly with 4 portions of the ammonium hydroxid instead of 3.) Combine 
the alkaline aqueous extracts, acidify, again extract with ether and wash the com- 
bined ether extracts as directed above. Distil slowly the gieater portion of the 
ether, allow the remainder to evaporate spontaneously and proceed as directed in 5. 

5 DETERMINATION. 

Dissolve the residue, obtained in 4, in a small amount of hot water and, after 
cooling, dilute to a definite volume (usually 50-100 cc), dependent on the amount 
of salicylic acid present. If the solution is not clear, filter through a dry filter. 
Dilute aliquots of the solution and treat with a few drops of 0.5% ferric chlorid 
solution or 2% ferric alum solution. 

The ferric alum solution should be boiled until a precipitate appears, allowed to 
settle, and filtered. The acidity of the solution is slightly increased in this manner, 
but it remains clear for a considerable time, and the turbidity caused by its dilution 
with water is much less and does not appear as soon as when the unboiled solution 
is used. This turbidity interferes with the exact matching of the color. 

Compare the colors developed with that obtained when a standard salicylic acid 
solution (containing 1 mg. of salicylic acid in 50 cc.) is similarly treated, using 
Nessler tubes or a colorimeter. In either case, and especially with ferric chlorid, 
avoid an excess of the reagent, although an excess of 0.5 cc. of 2% ferric alum solu- 
tion may be added to 50 cc. of the comparison solution of salicylic acid without 
impairing the results. 

BENZOIC ACID. 
PREPARATION OF SAMPLE. 

6 General Method. 

If solid or semi-solid, grind the sample, and mix thoroughly. Transfer about 
150 grams to a 500 cc. graduated flask, add enough pulverized sodium chlorid to 
saturate the water in the sample, render alkaline with sodium hydroxid solution 
or milk of lime, and dilute to the mark with a saturated salt solution. Allow to 
stand for at least 2 hours, with frequent shaking, and filter. If the sample contains 
large amounts of matter precipitable by salt solution, it is advisable to follow a 
method similar to that given under 7 (d). When alcohol is present, follow the 
method given under 7 (C). When large amounts of fats are present, make an 
alkaline extraction of the filtrate before proceeding as directed under 1 1 . 

7 Special Methods. 

(a) Ketchup. — Saturate the water in 150 grams of ketchup by adding 15 grams of 
pulverized sodium chlorid. Transfer the mixture to a 500 cc. graduated flask, rins- 
ing with about 150 cc. of saturated sodium chlorid solution. Make slightly alkaline 
to litmus paper with strong sodium hydroxid solution and fill to the mark with satu- 
rated salt solution. Allow to stand for at least 2 hours, shaking frequently. 
Squeeze through a heavy muslin bag and then filter through a large folded filter. 

(b) Jellies, jams, preserves and marmalades. — Dissolve 150 grams of the sam- 
ple in about 300 cc. of saturated salt solution. Add 15 grams of pulverized sodium 
chlorid. Make alkaline to litmus paper with milk of lime. Transfer to a 500 cc. 
graduated flask and dilute to the mark with saturated salt solution. Allow to 



144 ■ METHODS OF ANALYSIS [Chap. 

stand for at least 2 hours, shaking frequently, centrifugalize if necessary, and 
filter through a large folded filter. 

(C) Cider containing alcohol, and similar products. — Make 250 cc. of the sample 
alkaline to litmus paper with sodium hydroxid solution and evaporate on the steam 
bath to about 100 cc. Transfer the sample to a 250 cc. graduated flask, add 30 grams 
of pulverized sodium chlorid and shake until dissolved. Dilute to the original 
volume, 250 cc, with saturated salt solution, allow to stand for at least 2 hours, 
shaking frequently, and filter through a folded filter. 

(d) Sailed or dried fish. — Wash 50 grams of the ground sample into a 500 cc. gradu- 
ated flask with water. Make slightly alkaline to litmus paper with strong sodium 
hydroxid solution and dilute to the mark with water. Allow to stand for at least 
2 hours, shaking frequently, and then filter through a folded filter. Pipette accu- 
rately as large a portion of the filtrate as possible (at least 300 cc.) into a second 
500 cc. flask. Add 30 grams of the pulverized sodium chlorid for each 100 cc. of 
solution. Shake until the salt has dissolved and dilute to the mark with saturated 
salt solution. Mix thoroughly and filter oflf the precipitated protein matter on 
a folded filter. 

8 DETECTION AND ESTIMATION. 

Extract benzoic acid as directed under 2 or 4. If benzoic acid is present in 
considerable quantity, it will crystallize from the ether in shining leaflets having 
a characteristic odor on heating. Dissolve the residue in hot water, divide into 
2 portions, and test according to 9 or 10. 

9 Ferric Chlorid Test. — Qualitative. 

Make the solution from 8 alkaline with ammonium hydroxid, expel the excess of 
ammonia by evaporation, dissolve the residue in water, and add a few drops of a 
neutral 0.5% ferric chlorid solution. A brownish precipitate of ferric benzoate 
indicates the presence of benzoic acid. 

10 Modified Mohler Test.^ — Qualitative. 

Add to the water solution, prepared as described under 8, 1-3 cc. of N/3 sodium 
hydroxid and evaporate to dryness. To the residue, add 5-10 drops of concentrated 
sulphuric acid and a small crystal of potassium nitrate. Heat for 10 minutes in 
a glycerol bath at 120°-130°C., or for 20 minutes in a boiling water bath. The 
temperature must not exceed 130°C. After cooling add 1 cc. of water and make 
distinctly ammoniacal; boil the solution to decompose any ammonium nitrite which 
may have been formed. Cool and add a drop of fresh, colorless ammonium sulphid, 
without allowing the layers to mix. A red-brown ring indicates benzoic acid. 
On mixing, the color diffuses through the whole liquid and, on heating, finally changes 
to greenish yellow. This differentiates benzoic acid from salicylic acid or cinnamic 
acid. The last two form colored compounds, which are not destroyed by heating. 
The presence of phenolphthalein interferes with this test. 

11 Quantitative Method. 

Pipette a convenient portion (100-200 cc.) of the filtrate, obtained in 8 or 7, into a 
separatory funnel. Neutralize the solution to litmus paper with hydrochloric 
acid (1 to 3) and add an excess of 5 cc. of the same acid. In the case of salted fish 
a precipitation of protein matter usually occurs on acidifying, but the precipitate 
does not interfere with the extraction. Extract carefully with chloroform, using 
successive portions of 70, 50, 40, and 30 cc. To avoid an emulsion, shake cautiously 



X] FOOD PRESERVATIVES 145 

each time. The chloroform layer usually separates readily after standing a few 
minutes. If an emulsion forms, break it: (1) by stirring the chloroform layer with 
a glass rod; (2) by drawing it off into a second funnel and giving 1 or 2 sharp shakes 
from one end of the funnel to the other; or (3) by centrifugalizing for a few moments. 
As this is a progressive extraction, draw off carefully as much of the clear chloro- 
form solution as possible after each extraction, but do not draw off any of the emul- 
sion with the chloroform layer. If this precaution is taken, the chloroform extract 
need not be washed. 

Transfer the combined chloroform extracts to a porcelain evaporating dish, 
rinse the container several times with a few cc. of chloroform, and evaporate to 
dryness at room temperature in a current of air dried over calcium chlorid. 

The extract may also be transferred from the separatory funnel to a 300 cc. Erlen- 
meyer flask, rinsing the separatory funnel 3 times with 5-10 cc. of chloroform. Dis- 
til very carefully to about one fourth the original volume, keeping the temperature 
down so that the chloroform comes over in drops, not in a steady stream. Then 
transfer the residue to a porcelain evaporating dish, rinsing the flask 3 times with 
5-10 cc. portions of chloroform, and allow to evaporate to dryness spontaneously. 

Dry the residue overnight (or until no odor of acetic acid can be detected if the 
product is a ketchup) in a desiccator containing sulphuric acid. Dissolve the resi- 
due of benzoic acid in 30-50 cc. of neutral alcohol, add about one fourth this volume 
of water, 1 or 2 drops of phenolphthalein, and titrate with N/20 sodium hydroxid 
(1 cc. is equivalent to 0.0072 gram of anhydrous sodium benzoate). 

SACCHARIN. 

12 Qualitative Test. 

Extract with ether (after maceration and exhaustion with water, if necessary )j 
as directed in 1 and 4. Allow the ether extract to evaporate spontaneously and 
note the taste of the residue. The presence of saccharin, to the extent of 20 mg, 
per liter, is indicated by a sweet taste. Confirm by heating with sodium hydroxide 
as described below, and detecting the salicylic acid formed thereby. A sweet taste, 
suggesting the presence of a trace of saccharin, has been obtained frequently in 
saccharin-free wines, due to the so-called "false saccharin". 

Acidify 50 cc. of a liquid food or the aqueous extract of 50 grams of a solid or semi- 
solid, prepared as directed in 1 (C), and extract with ether as directed in 13. Dis- 
solve the residue, remaining after evaporation of the ether, in a little hot water 
and test a small portion of this solution for salicylic acid as directed under 2 or 3. 
Dilute the remainder of the solution to about 10 cc, and add 2 cc. of sulphuric 
acid (1 to 3). Heat to boiling and add a slight excess of 5% potassium perman- 
ganate solution, drop by drop; partly cool the solution, dissolve a piece of sodium 
hydroxid in it, and filter the mixture into a silver dish (silver crucible lids are well 
adapted to the purpose); evaporate to dryness and heat for 20 minutes at 210°- 
215°C. Dissolve the residue in water, acidify with hydrochloric acid and test the 
ether extract for salicylic acid as directed under 2 or 3. By this method all the 
so-called "false saccharin" and the salicylic acid naturally present (also added 
salicylic acid when not present in too large an amount) are destroyed, while 5 mg. 
of saccharin per liter are detected with certainty. 

13 Quantitative Method. 

Pipette 100 cc. of the sample, or a convenient portion of a solution, prepared 
as directed under 1 , representing not less than 20 grams of the sample, into a sepa- 



146 METHODS OF ANALYSIS [Chap. 

ratory funnel, make the solution neutral to litmus with dilute hydrochloric acid 
(1 to 3) and then add concentrated hydrochloric acid in the proportion of 5 cc. for 
each 100 cc. of solution. Extract with 4 separate portions of ether using, for each 
extraction, a volume of ether equivalent to half the volume of the aqueous layer. 
If the mixture emulsifies on shaking, this difficulty may be overcome as directed 
under 4. Wash the combined ether extracts with two 5 cc. portions of water, re- 
move the ether by distillation, and transfer the residue into a platinum crucible 
by means of a small amount of ether.. Evaporate the ether on a steam bath, add 
about 2-3 cc. of 10% sodium carbonate solution to the residue, rotate so that all 
of the residue is brought into contact with the solution, and evaporate to dryness 
on a steam bath. Add 4 grams of a mixture of equal parts of anhydrous sodium and 
potassium carbonates, heat gently at first, and then to complete fusion for 30 minutes 
over an alcohol or other sulphur-free flame. Cool, dissolve the melt in water, acidify 
with hydrochloric acid and determine the sulphate present as barium sulphate. 
Correct the result thus obtained for any sulphur present in the fusion mixture as 
found in a blank determination. Calculate the amount of saccharin in the sample 
by multiplying the weight of barium sulphate by 0.7845. 

BORIC ACID AND BORATES. 

14 Qualitative Test.' 

Preliminary test. — Immerse a strip of turmeric paper in the sample acidified 
with hydrochloric acid in the proportion of 7 cc. of concentrated acid to each 100 
cc. of sample, and allow the paper to dry spontaneously. If borax or boric acid is 
present, the paper will acquire a peculiar red color, changed by ammonium hydroxid 
to a dark blue-green but restored by acid. Solid or pasty samples may be heated 
with enough water to make them sufficiently fluid, concentrated hydrochloric acid 
added in about the proportion of 1 to 13 and the liquid tested in the same way. 

Confirmatory test. — Make about 25 grams of the sample decidedly alkaline with 
lime water and evaporate to dryness on a water bath. Ignite the residue to de- 
stroy organic matter. Digest with about 15 cc. of water, add concentrated hydro- 
chloric acid, drop by drop, until the ignited residue is dissolved, and then add 1 cc. 
in excess. Saturate a piece of turmeric paper with the solution, and allow it to 
dry without the aid of heat. In the presence of borax or boric acid, the color change 
will be the same as given above. 

1 5 Quantitative Method.* 

Make 10-100 grams of the sample (depending upon the nature of the sample 
and the amount of boric acid present) distinctly alkaline with sodium hydroxid 
solution and evaporate to dryness in a platinum dish. Ignite the residue until 
organic matter is destroyed, avoiding an intense red heat, cool, digest with about 
20 cc. of hot water, and add hydrochloric acid, drop by drop, until the reaction is 
distinctly acid. Filter into a 100 cc. flask, and wash with a little hot water, the 
volume of the filtrate not to exceed 50-60 cc. Return the filter containing any 
unburned carbon to the platinum dish, make alkaline by wetting thoroughly with 
lime water, dry on a steam bath and ignite to a white ash. Dissolve the ash in 
a few cc. of dilute hydrochloric acid and add to the liquid in the 100 cc. flask, rins- 
ing the dish with a few cc. of water. To the combined solutions, add 0.5 gram of 
ealcium chlorid and a few drops of phenolphthalein, then 10% sodium hydroxid 
solution until a permanent light pink color is produced, and finally dilute to 



X] FOOD PRESERVATIVES 147 

the mark with lime water. Mix and filter through a dry filter. To 50 cc. of the 
filtrate add N/1 sulphuric acid until the pink color disappears, then add methyl 
orange, and continue the addition of the acid until the yellow color is changed to 
pink. Boil for about 1 minute to expel carbon dioxid. Cool, and carefully add 
N/5 sodium hydroxid until the liquid assumes a yellow tinge, avoiding an excess 
of the alkali. All the boric acid is now in a free state with no uncombined sulphuric 
acid present. Add a little phenolphthalein, and an equal volume of neutral glycerol. 
Titrate with N/5 sodium hydroxid until a permanent pink color is produced. About 
10 grams of mannitol may be substituted for the glycerol in this determination. 
At the end of the titration add an additional 2 grams and continue the titration if 
the pink color is discharged. Repeat the alternate addition of mannitol and alkali 
until a permanent end point is reached. 

One cc. of N/5 sodium hydroxid is equivalent to 0.0124 gram of boric acid. 

FORMALDEHYDE, 

1 6 PREPARATION OF SAMPLE. 

If solid or semi-solid, macerate 200-300 grams of the material with about 100 cc. 
of water in a mortar. Transfer to a short-necked, 500-800 cc. copper or glass dis- 
tillation flask and make distinctly acid with phosphoric acid, connect with a con- 
denser and distil 40-50 cc. In the case of highly colored liquids, the same method 
of preparation should be employed. 

In the case of meats and fats, extract the formaldehyde with alcohol and use the 
filtrate. In the case of fat, heat the mixture above the melting point of the fat to 
insure thorough extraction. In the case of milk, shake with an equal volume of 
strong alcohol and use the filtrate. Shake othei liquids with an equal volume of 
strong alcohol and filter from any insoluble matter. 

QUALITATIVE TESTS. 

17 Phenylhydrazin Hydrochlorid Method.^ 

Mix 5 cc. of the distillate, as prepared under 16, or of an alcoholic solution or 
extract obtained as directed above, with 0.03 gram of phenylhydrazin hydrochlorid, 
and 4 or 5 drops of a 1% ferric chlorid solution. Add slowly and with agitation, 
in a bath of cold water to pre\ent heating the liquid, 1-2 cc. of concentrated sul- 
phuric acid. Dissolve the precipitate by the addition either of concentrated sul- 
phuric acid (keeping the mixture cool) or alcohol. In the presence of formaldehyde 
a red color develops. 

This method gives reliable reactions for formaldehyde in solutions of formalde- 
hyde varying from 1 part in 50,000 to 1 part in 150,000. Acetaldehyde and benz- 
aldehyde give no reaction when treated by this method and do not interfere with 
the reaction given by formaldehyde. 

18 Hehner Method.^ 

Mix about 5 cc. of the distillate, obtained in 16, with an equal volume of pure 
milk, or a 1-2% solution of egg albumen, in a test tube and underlay with strong 
commercial sulphuric acid without mixing. A violet or blue color at the junction 
of the two liquids indicates formaldehyde. This color is given only in the presence 
of a trace of ferric chlorid or other oxidizing agent. As pointed out by Hehner, 
milk may be treated directly by this method and gives positive tests in the presence 
of 1 or more parts of formaldehyde per 10,000. Some other articles of food rich 
in proteins, for example, egg albumen, give the reaction in the presence of water 
without the addition of milk. 



148 METHODS OF ANALYSIS [Chap. 

1 9 Leach Method. 

Mix about 5 cc. of the distillate, obtained under 16, with an equal volume of pure 
milk in a porcelain casserole and add about 10 cc. of concentrated hydrochloric 
acid, containing 1 cc. of 10% ferric chlorid solution, to each 500 cc. of acid. Heat 
to 80°-90°C. directly over the gas flame, rotating the casserole to break up the curd. 
A violet coloration indicates formaldehyde. 

Rimini Methods 

20 Phenylhydrazin Hydrochlorid and Sodium Nitro-prussid Test. 

This method may be applied directly to liquid foods, to an aqueous or alcoholic 
extract of solid foods, or to the distillate prepared as directed in 16. In the case 
of milk, apply the method directly. In the case of meat, comminute the sample, 
extract with 2 volumes of hot water, and employ the expressed liquid for the test. 
Heat fats above their melting point with 10 cc. of alcohol, shake thoroughly, cool, 
filter through a moistened filter, and use the filtrate for the test. 

Dissolve a lump of phenylhydrazin hydrochlorid about the size of a pea in 3-5 
cc. of the liquid to be tested, add 2-4 drops (not more) of a 5-10% sodium nitro- 
prussid solution and 8-12 drops of an approximately 12% sodium hydroxid solution. 
If formaldehyde is present, a green or blue color develops depending upon the 
amount. When formaldehyde is present to the extent of more than 1 part in 70,000- 
80,000 in the solution tested, a distinct green or bluish green reaction is obtained. 
In more dilute solutions the green tint becomes less marked and a yellow tinge tend- 
ing toward greenish brown develops. 

With this method acetaldehyde and benzaldehyde give a color varying from 
red to brown, according to the strength of the solution. A reaction may there- 
fore be obtained with these aldehydes similar to that obtained with formaldehyde 
in solutions more dilute than 1 part in 70,033. The presence of acetaldehyde or 
benzaldehyde together with formaldehyde gives a yellowish or yellowish green 
tinge. The reaction for formaldehyde may therefore be masked by the presence 
of other aldehydes, but is characteristic when a clear green color is obtained. 

21 Phenylhydrazin Hydrochlorid and Potassium Ferricyanid Test. 

Proceed as directed in 20, substituting a solution of potassium ferricyanid for 
the sodium nitro-prussid. Formaldehyde gives a red color. Alcoholic extracts 
from foods must be diluted with water to prevent the precipitation of potassium 
ferricyanid. The test is not applicable in the presence of the coloring matter of 
blood. 

22 Phenylhydrazin Hydrochlorid and Ferric Chlorid Test. 

Treat 15 cc. of milk or other liquid food or of the distillate, prepared as directed 
under 16, with 1 cc. of a dilute phenylhydrazin hydrochlorid solution, then with 
a few drops of dilute ferric chlorid solution and, finally, with concentrated hydro- 
chloric acid. The presence of formaldehyde is indicated by the formation of a 
red color, which changes after some time to orange yellow. 

Milk may be examined directly by this method, but more delicate tests may be 
obtained from the distillate from milk or from milk serum. Acetaldehyde or benz- 
aldehyde does not interfere with the reaction. 



X] FOOD PRESERVATIVES 149 

23 Phloroglucol Method.' 

To 10 cc. of milk or other liquid food under examination in a test tube add, by 
means of a pipette, 2 cc. of phloroglucol reagent (1 gram of phloroglucol, 20 grams of 
sodium hydroxid and water to make 100 cc), placing the end of the pipette on the 
bottom of the tube in such a manner that the reagent will form a separate layer. 

If formaldehyde be present, a bright red coloration (not purple) forms at the 
zone of contact. This solution gives a yellow color in the presence of some alde- 
hydes, and, if it is used for the detection of aldehyde formed by the oxidation of 
methyl alcohol after the destruction of ethyl aldehyde with hydrogen peroxid, an 
orange yellow color will slowly appear when an insufficient amount of hydrogen 
peroxid has been employed. On the other hand, if the excess of hydrogen 
peroxid is not fully destroyed before the use of this reagent, a purple color develops 
slowly. The clear, red color given by the use of this reagent forms quickly, and, 
in the presence of but a small amount of formaldehyde fades rapidly. 

FLUORIDS. 

QUALITATIVE TESTS. 

24 Method I.— Modified Method of Blarez.^ 

Thoroughly mix the sample and boil 150 cc. (in the case of solid foods an aqueous 
extract may be employed provided the fluorids are in a soluble form). Add to the 
boiling liquid 5 cc. of 10% potassium sulphate solution and 10 cc. of 10% barium 
acetate solution. Collect the precipitate in a compact mass (a centrifuge may be 
used advantageously) and wash upon a small filter. Transfer to a platinum crucible 
and ignite. 

Dip a carefully cleaned glass plate, while hot, in a mixture of equal parts of Car- 
nailba wax and paraffin and allow to cool. Make, with a sharp instrument, a dis- 
tinctive mark through the wax, taking care not to scratch the surface of the glass. 

Add a few drops of concentrated sulphuric acid to the residue in the crucible 
and cover with the waxed plate, having the mark nearly over the center and mak- 
ing sure that the edge of the crucible is in close contact with it. Keep the top sur- 
face of the plate cool by means of a suitable device and heat the crucible for an hour 
at as high a temperature as practicable without melting the wax (an electric stove 
gives the most satisfactory form of heat). 

If fluorids be present, a distinct etching will be apparent on the glass where it 
was exposed. 

25 Method II. 

The preceding method may be varied by mixing a small amount of precipitated 
silica with the precipitated barium fluorid and applying the method for the detection 
of fluosilicates, under 27 or 28. 

This method is of value in the case of foods whose ash contains a considerable 
amount of silica. Under these circumstances, concentrated sulphuric acid liber- 
ates silicon fluorid, which would escape detection under 24. 

FLUOBORATES AND FLUOSILICATES. 
28 PREPARATION OF SAMPLE. 

Make about 200 grams of the sample alkaline with lime water, evaporate to dry- 
ness, and incinerate. Extract the crude ash with water, to which sufficient acetic 



150 METHODS OF ANALYSIS [Chap. 

acid has been added to decompose carbonates, filter, ignite the insoluble portion, 
extract with dilute acetic acid, and again filter. The insoluble portion now con- 
tains calcium silicate and fluorid, while the filtrate will contain all the boric acid 
present. 

QUALITATIVE TESTS. 

27 Method /." 

Incinerate the filter, from 26, containing the insoluble portion, mix with a little 
precipitated silica, transfer to a short test tube, attached to a small U-tube contain- 
ing a few drops of water and add 1-2 cc. of concentrated sulphuric acid. Keep 
the test tube in a beaker of water on the steam bath for 30-40 minutes. If any 
fluorin be present, the silicon fluorid generated will be decomposed by the water 
in the U-tube and will form a gelatinous deposit on the walls of the tube. 

Next test the filtrate as directed under 14. If both hydrofluoric and boric acids 
be present, it is probable that they are combined as borofluorid. If, however, 
silicon fluorid is detected and not boric acid, the operation should be repeated with- 
out the introduction of the silica, in which case the formation of the silicon skeleton 
is conclusive evidence of the presence of fluosilicate. In an ash containing an ap- 
preciable amount of silica, sulphuric acid will liberate silicon fluorid rather than 
hydrofluoric acid. The presence of a fluosilicate is indicated, therefore, and not 
the presence of a fluorid. 

28 Method II. 

Incinerate the filter, from 26, containing the insoluble portion, in a platinum 
crucible, mix with a little precipitated silica, and add 1 cc. of concentrated sul- 
phuric acid. Cover the crucible with a watch glass, from the underside of which 
a drop of water is suspended, and heat for an hour at 70°-80°C., keeping the watch 
glass cooled. The silicon fluorid which is formed is decomposed by the water, leav- 
ing a gelatinous deposit of silica and etching a ring at the periphery of the drop 
of water. Test the filtrate for boric acid as directed under 1 4. 

SULPHUROUS ACID. 

29 Qualitative TesL" 

Add some sulphur-free zinc, and several cc. of hydrochloric acid to about 25 
grams of the sample (with the addition of water, if necessary) in a 200 cc. Erlen- 
meyer flask. In the presence of sulphites, hydrogen sulphid will be generated 
and may be detected with lead acetate paper. Traces of metallic sulphids are 
occasionally present in vegetables, and will give the same reaction as sulphites 
under the conditions of the above test. Positive results obtained by this method 
should be verified by the distillation method under 30. 

It is always advisable to make the quantitative determination of sulphites, 
owing to the danger that the test may be due to traces of sulphids. A trace is not 
to be considered sufficient indication of the presence of sulphur dioxid either as a 
bleaching agent or as a preservative. 

TOTAL SULPHUROUS ACID. 

30 Method I. — Distillation Method. 

Distil 20-100 grams of the sample (adding recently boiled water if necessary) 
in a current of carbon dioxid, after the addition of about 5 cc. of a 20% glacial phos- 



X] FOOD PRESERVATIVES 151 

phoric acid solution, until 150 cc. have passed over. Collect the distillate in about 
100 cc. of nearly saturated bromin water, allowing the end of the condenser to dip 
below the surface. The method and apparatus may be simplified without material 
loss in accuracy by omitting the current of carbon dioxid, adding 10 cc. of phosphoric 
acid instead of 5 cc, and dropping into the distillation flask, immediately before 
attaching the condenser, a piece of sodium bicarbonate weighing not more than 
1 gram. The carbon dioxid liberated is not sufiicient to expel the air entirely from 
the apparatus, but will prevent oxidation to a large extent. When the distillation 
is finished, boil off the excess of bromin, dilute the solution to about 250 cc, add 5 
cc. of hydrochloric acid (1 to 3), heat to boiling, and precipitate the sulphuric acid 
with 10% barium chlorid solution. Boil for a few minutes longer, allow to stand 
overnight in a warm place, filter on a weighed Gooch, wash with hot water, ignite 
at a dull red heat, and weigh as barium sulphate. 

31 Method II. — Direct Titration Method. 

In the examination of wine, fairly accurate results may be obtained by the fol- 
lowing method : 

Place 25 cc. of 5.6% potassium hydroxid solution in a 200 cc. flask. Introduce 
50 cc. of the sample, mix with the potassium hydroxid solution, and allow the mix- 
ture to stand for 15 minutes with occasional agitation. Add 10 cc. of sulphuric acid 
(1 to 3) and a few cc. of starch solution, and titrate the mixture with N/50 iodin solu- 
tion. Introduce the iodin solution as rapidly as possible and continue the addition 
until the blue color persists for several minutes. One cc of N/50 iodin is equiva- 
lent to 0.00064 gram of sulphur dioxid. 

DETERMINATION OF FREE SULPHUROUS ACID. 

32 (Especially Adapted to Wine.) 

Treat 50 cc. of the sample in a 200 cc. flask with about 5 cc. of sulphuric acid 
(1 to 3) add about 0.5 gram of sodium carbonate to expel the air, and titrate the sul- 
phurous acid with N/50 iodin, as directed under 31 . 

BETA-NAPHTHOL. 

33 Qualitative Test. 

Extract 200 cc. of the sample, or of its aqueous extract, prepared as directed 
under 1 (C), with 10 cc. of chloroform in a separatory funnel. To the chloroform 
extract in a test tube add a few drops of alcoholic potash, and place in a boiling 
water bath for 2 minutes. The presence of beta-napthol is indicated by the forma- 
tion of a deep blue color, which changes to green and then to yellow. 

ABRASTOL. 

QUALITATIVE TESTS. 

34 Sinibaldi Method.^^ 

Make 50 cc. of the sample alkaline with a few drops of ammonium hydroxid and 
extract with 10 cc. of amyl alcohol, adding ethyl alcohol if an emulsion is formed. 
Decant the amyl alcohol, filter if turbid, and evaporate to dryness. Add to the 
residue 2 cc. of nitric acid (1 to 1), heat on the water bath until half of the liquid 
is evaporated, and transfer to a test tube with the addition of 1 cc. of water. Add 
about 0.2 gram of ferrous sulphate and an excess of ammonium hydroxid, drop by 



152 METHODS OF ANALYSIS [Chap. 

drop, with constant shaking. If the resultant precipitate is of a reddish color, 
dissolve it in a few drops of sulphuric acid, and add ferrous sulphate and ammonium 
hydroxid as before. As soon as a dark colored or greenish precipitate is obtained, 
introduce 5 cc. of alcohol, dissolve the precipitate in sulphuric acid, shake well and 
filter. In the absence of abrastol this method gives a colorless or light yellow liquid, 
while a red color is produced in the presence of 0.01 gram of abrastol. 

35 SangU-Ferrihre MethodJ^ 

Boil 200 cc. of the sample with 8 cc. of concentrated hydrochloric acid for an 
hour in a flask fitted with a reflux condenser. Abrastol is thus converted into beta- 
naphthol and is detected as directed under 33. 

SUCROL OR DULCIN. 
QUALITATIVE TESTS. 

36 M or pur go Method.^* 

Evaporate about 100 cc; of the sample, or of the aqueous extract prepared as 
directed under 1 (C) and neutralized with acetic acid, to a sirupy consistency after 
the addition of about 5 grams of lead carbonate, and extract the residue several 
times with 90% alcohol. Evaporate the alcoholic extract to dryness, extract the 
residue with ether, and allow the ether to evaporate spontaneously in a porcelain 
dish. Add 2 or 3 drops each of phenol and concentrated sulphuric acid and heat 
for about 5 minutes on the water bath, cool, transfer to a test tube and overlay with 
ammonium hydroxid or sodium hydroxid solution with the least possible mixing. 
The presence of dulcin is indicated by the formation of a blue color at the zone of 
contact. 

37 Jorissen Method.^'' 

Suspend the residue from the ether extract obtained as directed above in about 
5 cc. of water; add 2-4 cc. of an approximately 10% solution of mercuric nitrate, 
and heat for 5-10 minutes on the water bath. In the presence of sucrol a violet blue 
color is formed, which is changed to a deep violet on the addition of lead peroxid. 

FORMIC ACID. 

Quantitative Method.^^ 

38 REAGENTS. 

(a) Sodium acetate solution. — Dissolve 50 grams of dry sodium acetate in suffi- 
cient water to make 100 cc. and filter. 

(b) Mercuric chlorid reagent. — Dissolve 100 grams of mercuric chlorid and 150 
grams of sodium chlorid in sufficient water to make 1 liter and filter. 

(C) Tartaric acid. 

(d) Barium carbonate. 



39 



APPARATUS. 



The apparatus required (Fig. 6) consists of a steam generator (S), a 300 cc. flask 
(A) in which the sample is placed, a 500 cc. flask (5), containing a suspension of bari- 
um carbonate, a spray trap (T), a condenser, and a 1 liter graduated flask (C). 
The tip of the tube (D), leading into (B), consists of a bulb containing a number 
of small holes to break the vapor into small bubbles. 



X] 



FOOD PRESERVATIVES 



153 




FIG. 6. APPARATUS FOR DETECTION OF FORMIC ACID. 



40 



DETERMINATION. 



For thin liquids like fruit juices, use 50 cc. For heavy liquids and semi-solids 
like sirups and jams, use 50 grams diluted with 50 cc. of water. Place the sam- 
ple in the flask (A), add 1 gram of tartaric acid, and connect as shown in Fig. 6, 
the flask (B) having been charged previously with a suspension of 2 grams of barium 
carbonate in 100 cc. of water. If much acetic acid is present, sufficient barium 
carbonate must be used so that at least 1 gram remains at the end of the operation. 
Heat the contents of flasks (A) and (B) to boiling and distil with steam from the 
generator (S), the vapor passing first through the sample in flask (A), then through 
the boiling suspension of barium carbonate in (B), after which it is condensed, and 
measured in the graduated flask (C). Continue the distillation until 1 liter of dis- 
tillate is collected, maintaining the volume of the liquids in the flasks (A) and {B) 
as nearly constant as possible by heating with small Bunsen flames, and avoid- 
ing charring of the sample in the flask (A). After 1 liter of distillate has been col- 
lected, disconnect the apparatus and filter the contents of flask (B) while hot, wash- 
ing the barium carbonate with a little hot water. The filtrate and washings should 
now measure about 150 cc. If not they should be boiled down to that volume. Then 
add 10 cc. of the sodium acetate, 2 cc. of 10% hydrochloric acid, and 25 cc. of the 
mercuric chlorid reagent. Mix thoroughly and immerse the container in a boil- 
ing water bath or steam bath for 2 hours. Then filter on a tared Gooch, wash the 
precipitate thoroughly with cold water and finally with a little alcohol. Dry in a 
boiling water oven for 30 minutes, cool, weigh, and calculate the weight of formic 
acid present by multiplying the weight of the precipitate by 0.0975. If the weight 
of mercurous chlorid obtained exceeds 1.5 grams, the determination must be re- 
peated, using more mercuric chlorid reagent or a smaller amount of sample. A blank 



154 METHODS OF ANALYSIS 

test should be conducted with each new lot of reagents employed in the reduction, 
using 150 cc. of water, 1 cc. of 10% barium chlorid solution, 2 cc. of 10% hydrochloric 
acid, 10 cc. of the sodium acetate, and 25 cc. of the mercuric chlorid reagent, heat- 
ing the mixture in a boiling water bath or steam bath for 2 hours. The weight of 
mercurous chlorid obtained in this blank test must be deducted from that obtained 
in the regular determination. 

BIBLIOGRAPHY. 

1 J. Ind. Eng. Chem., 1910, 2: 24. 

2 Z. Nahr. Genussm., 1910, 19: 137; C. A., 1910, 4: 1523. 

3 U. S. Div. Chem. Bull. 51, p. 113. 

* Sutton. Volumetric Analysis. 10th ed., 1911, p. 95. 
B Z. Nahr. Genussm., 1902, 5: 353. 

6 Analyst, 1895, 20: 155. 

' Ann. di farmacoterapia e chim., 1898, 27: 97; Chem. Zentr., 1898, (1), 1152; 1902, 
(1), 1076; J. Soc. Chem. Ind., 1898, 17: 697; Chem. Ztg., 1902, 26: 246; Abs. J. Chem. 
Soc, 1902, 82: 367. 

* Service de Surveillance des Aliments en Belgique, through Bui. soc. chim. belg., 
1897-8, 11-12: 211; Abs. Analyst, 1897, 22: 282. 

9 Chem. News, 1905, 91: 39; Ann. Rept. Mass. State Board of Health, 1905, p. 498 

i« Mon. Sci., 1895, (4), 9: 324. 

" U. S. Div. Chem. Bull. 13, (8), p. 1032. 

12 Mon. Sci., 1893, (4), 7: 842. 

'» Compt. rend., 1893, 117: 796. 

'* Z. anal. Chem., 1896, 35: 104 

" Ibid., 628. 

»• Biochem. Z., 1913. 51: 253. 



JOURNAL 

OF THE 

ASSOCIATION OF OFFICIAL 
AGRICULTURAL CHEMISTS 



Vol. II " AUGUST 15, 1916 No. 2 



BOARD OF EDITORS 
C. L. ALSBiBRa, Chairman 

R. E. DOOLITTLB J. P. StBKBT 

E. F. Laod L. L. Van Sltkb 

PART II 

Report of Committee on Editing Methods of Analysis 

Coloring Matters in Foods 

Metals in Foods 

Fruits and Fruit Products 

Canned Vegetables 

Cereal Foods 

Wines 

Distilled Liquors 

Beers 

Vinegars 



PUBLISHED QUARTERLY BY 

THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS 

WILLIAMS & WILKINS COMPANY 

BALTIMORE, U. S. A. 

THE CAMBRIDGE UNIVERSITY PRESS 

FETTER LANE, LONDON, E. C. I 

iHHHaHHaHaaBaaHngBnBRxaBHnBBaiwiNauuuujwuujjiMHiHBannggrian^ 

Katared ■» aacood-cUsn matter August 23, 1915, at the Poat-Oflice at BaltiiDore, Maryland, undnr til* Aet <A Aucuat 24, lOU 
Copyright IIUO by AsMwiatuw of O£oial A«jrioultur») CiMatisU 



13 1916 
)CI.B369681 C^ 



XI. COLORING MATTERS IN FOODS.— TENTATIVE. 

(An italicized number, following immediately the name of a dye, is the 

number by which that dye is designated in "A Systematic Survey of 

the Organic Colouring Matters", 1904, by Arthur Green, 

based on the German of Schultz and Julius.) 

1 PIGMENTS. 

The insoluble pigments, ultramarine, lampblack, etc., are most commonly used 
as facings and may be separated by washing the sample with water and allowing 
the washings to settle. The particles of coloring matter can be identified by micro- 
scopic examination and by treatment of the residue or purified coloring matter 
with chemical reagents. A large proportion of the common pigments other than 
lakes, such as the yellow, brown and red ochres and umbers, are derivatives of the 
heavy metals and contain iron, manganese, etc. Others, such as various green and 
blue compounds, including the green chlorophyll derivatives, contain copper. 
These pigments may be identified by the usual tests for the respective metals. The 
analytical properties of the insoluble coloring matters are described in various 
standard works, some of which are listed in the bibliography, especially "Farb- 
stofftabellen by Schultz'." 

Soluble Coloring Matters and Their Lakes, 
coal tar dyes. 

2 Wool dyeing test''. 

(a) Wines, fruit juices, distilled liquors, flavoring extracts, vinegars, beers, sirups, 
non-alcoholic beverages and similar products. — Dilute 20-200 cc. of the sample with 
1-3 volumes of water and boil or heat on the steam bath with a small piece of white 
woolen cloth (nun's veiling). When the mixture contains much alcohol, heat until 
most of the alcohol has been removed; in other cases, take out the wool after 
5-15 minutes and rinse vdth water. Then treat the liquid with 3 or 4 drops of con- 
centrated hydrochloric acid for each 100 cc. and warm again for 10-20 minutes with 
a clean piece of wool. The basic dyes go on the fiber best from neutral or faintly 
ammoniacal solutions and, if present, will appear on the first piece of wool. Acid 
colors dye from neutral solutions but more readily from those containing free acid. 
If the wool takes up any considerable amount of coloring matter in either case, the 
presence of coal tar dyes is indicated. The lichen colors' (Archil, Cudbear, Litmus) 
go readily on wool, however, and many other natural colors, such as Turmeric, will 
dye the fiber, if present in considerable amount. On the other hand, a few coal 
tar dyes, especially Auramine and Naphthol Green B, are quite unstable and, if 
present in small amounts, may give no distinct dyeing. Acid dyes are much more 
frequently used than basic dyes and in most cases may be removed from wool with- 
out much decomposition by "stripping" the latter with dilute ammonia^. By the 
action of the alkali, many natural colors are destroyed, while others remain for the 
most part on the fiber. If the behavior with wool in neutral and acid solutions 
indicates the presence of acid dyes, rinse the colored cloth thoroughly with water, 
cover with 2% ammonimn hydroxid solution in a casserole, boil for a few minutes, 
remove the cloth and squeeze out the adhering liquid. Boil the ammoniacal solu- 

155 



156 METHODS OF ANALYSIS [Chap. 

tion to remove the excess of ammonia, drop in a piece of clean, wet wool, make dis- 
tinctly but not strongly acid with hydrochloric acid and boil again. If acid coal 
tar dyes are present, they will usually give a fairly clean, bright dyeing on the second 
piece of wool. A further purification may be carried out by repeating the stripping 
and re-dyeing, though generally accompanied by corresponding loss of dye. 

(b) Candies and similar colored sugar ■products. — Dissolve about 20 grams of the 
sample in 100 cc. of water and treat the solution as directed under (a). When the 
coloring matter is on the surface of the candy, pour off the solution before the color- 
less inner portion has dissolved. 

(C) Jams and jellies. — Boil a mixture of 10-20 grams of the sample and 100 cc. 
of water with wool in neutral and also in acid solution as directed under (a). For 
thick jams it is usually better, though less easy, first to extract the coloring sub- 
stances by treating the product as directed under (d). 

(d) Canned and -preserved fruits and vegetables, sausage casings, smoked fish, coffee, 
spices, etc. — Macerate 20-200 grams of the sample with 4-5 times its weight of 80% 
alcohol. After standing a few hours pour off the solvent as completely as possible 
and repeat the extraction, using 70% alcohol containing about 1% of ammonia. 
(1) Examine separately the filtered alcoholic extracts as directed under (a); or, (2) 
Boil the ammoniacal solution until practically neutral, complete the neutralization 
with acetic acid, add the neutral 80% alcohol extract, continue the evaporation 
until most of the alcohol is removed, and boil with wool as directed under (a). 

(e) Cocoa and chocolate products. — Treat cocoa as directed under (d). The alco- 
holic extract will contain a large amount of natural coloring matter and several 
dyeings and strippings may be necessary to get rid of this in order to show the pres- 
ence of coal tar dyes. 

Chocolate may be treated similarly but the following procedure is preferable: 
Wash 20-200 grams of the well divided sample with gasoline on a filter until most of 
the fat has been removed; if the gasoline is colored, reserve for the examination of 
oil-soluble dyes as directed under 3. Remove most of the adherent solvent from the 
residue by evaporation or pressure between layers of absorbent paper and digest 
with alcohol as directed under (d). 

Coal tar dyes may also be detected in chocolate and cocoa products by mixing 
directly with 3-4 times their weight of hot water and immediately boiling the magma 
with wool, as directed under (a). Because of the presence of large amounts of fatty 
and protein materials, this method is not very satisfactory. 

(f) Cereal products. — Proceed as directed under (d), in most cases working with a 
large amount of the sample, 200-500 grams, and a relatively smaller amount of alcohol. 
Where tests are to be made only for the acid dyes, the extraction with neutral 
80% alcohol may be omitted advantageously. 

3 OIL-SOLUBLE DYES^ 

Prepare an alcoholic solution of the oil-soluble dj^e by one of the following methods 
which are to be applied to the oil or fat obtained by extraction with ether or gasoline 
if the nature of the substance requires it: 

(a) Shake the oil or melted fat with an equal volume of 90% alcohol. The alcohol 
after separation will contain Aniline Yellow, Butter Yellow, Aminoazotoluene and 
Auramine, if present. 

(b) Saponify 20-200 grams of the oil or fat with alcoholic potash and, after re- 
moval of most of the alcohol on the steam bath, extract the soap with ether or gaso- 
line. Most of the common dyes are removed by this treatment, though the digestion 
with strong alkali may cause some decomposition and make the extraction rather 
troublesome. 



XI] COLORING MATTERS IN FOODS 157 

(C) Dilute 20-200 grams of the oil or melted fat with 1-2 volumes of gasoline and 
shake out successively with 2-4% potassium or sodium hydroxid solution, 12-15% 
hydrochloric acid, and phosphoric-sulphuric acid mixture, prepared by mixing 
85% phosphoric acid with about 10-20% by volume of concentrated sulphuric acid. 

The dilute alkali extracts Sudan G and Annatto. The dilute hydrochloric acid 
extracts Aniline Yellow (7), Aminoazotoluene, and Butter Yellow (16), the first 2 
forming orange-red, the latter cherry-red solutions in this solvent. Benzeneazo- 
beta-naphthylamin and homologues also come in this group, though they are not 
extracted very readily and decompose rapidly on standing in strongly acid solution. 
The phosphoric acid mixture is necessary for the extraction of Sudan I (U), Sudan 
II (49), Sudan III (143), and the homologue of the last, Sudan IV. The procedure 
is not very suitable in the presence of Auramine but this dye is seldom found in oils. 
Neutralize the alkaline and dilute hydrochloric acid solutions ; dilute the phosphoric 
acid mixture and partially neutralize, cooling the liquid during this operation; 
and extract the dyes by shaking with ether or gasoline. 

For the direct dyeing test use the alcoholic solution, obtained as directed in (a). 
Evaporate to dryness the ether or gasoline solutions, obtained as directed in (b) and 
(C), and dissolve the residue in 10-20 cc. of strong alcohol. To the alcoholic solution 
add some strands of white silk and a little water and evaporate on the steam bath until 
the alcohol has been removed or until the dye is taken up by the silk. The dyeing 
test is sometimes unsatisfactory and in all cases a small portion of the alcoholic solu- 
tion should be tested by treating with an equal volume of concentrated hydrochloric 
acid and stannous chlorid solution. The common oil-soluble coal tar dyes are ren- 
dered more red or blue by the acid and are decolorized by the reducing agent. Most 
of the natural coloring matters become slightly paler with the acid and are little 
changed by the stannous chlorid solution. 

Separation of Coloring Matters in Pure Condition by Means of 
Immiscible Solvents". 

4 preparation of sample. 

(a) Water-soluble colors. — Proceed as directed under 2, omitting the fixation of 
the color on wool, and obtain an aqueous solution as free as practicable from sus- 
pended matter, alcohol, acids, alkalies and salts. 

(b) Water-insoluble lakes. — If the sample is in solid form, treat the well divided 
material with sufficient water to form a paste. Liquids require no preparation 
except the removal of alcohol when present. 

5 Mixtures of Orange I, Erythrosine, Indigo Carmine, Amaranth, 

Tartrazine, Naphthol Yellow S, Ponceau 3R and 
Light Green S F Yellowish. 

The use of immiscible solvents for the separation of mixtures of coloring matters 
usually involves a systematic fractionation since many of the dyes used do not differ 
very greatly in their solubilities in the various solvents. When it seems probable 
that only the 8 coal tar dyes permitted under the Federal Food and Drugs Act^ 
are present, the following abridged procedure may be used for their separation. For 
this procedure the concentration of the dye solution should lie preferably between 
0.01-0.05%. The solutions obtained in the examination of colored food products 
practically never require further dilution but with commercial food colors care must 
be taken that the concentration is not too high. Treat the sample, prepared as 
directed in 4, with one half its volume of concentrated hydrochloric acid and extract 
a few times with amyl alcohol. The use of the centrifuge is sometimes necessary 



158 METHODS OF ANALYSIS [Chap. 

to separate the layers. Designate the residual aqueous layer as A. Combine the 
aniyl alcohol extracts and wash with 4-5 portions of N/4 hydrochloric acid or until 
this solvent extracts very little color. These washings will contain any Indigo 
Carmine, Amaranth and Tartrazine present, the Indigo Carmine being removed in 
somewhat larger proportion in the first washings than the other 2. With ordinary 
concentration very little Ponceau will be removed. Designate these combined 
washings as B. 
Q ORANGE I AND ERYTHROSINE. 

Measure, if necessary, the amyl alcohol extract, under 5, then (1) Dilute with an 
equal volume of petroleum ether or low boiling gasoline, and again wash several 
times with N/4 hydrochloric acid to extract Ponceau 3R and Naphthol Yellow S; 
or, (2) Without dilution with gasoline, wash with 5% salt solution until these 2 dyes 
are extracted. Designate these washings as C. The Ponceau and Yellow having 
been removed, the amyl alcohol, containing an equal volume of gasoline, is washed 
a few times with water which will extract Orange I. This dye ha\ang been removed, 
shake the solution, although the latter may appear almost colorless, with very dilute 
sodium hydroxid solution to remove Erj^throsine. If considerable Orange I is present, 
some of it may contaminate the washings containing the Ponceau 3R and Naphthol 
Yellow S, especially when these have been separated by means of N/4 hydrochloric 
acid after the addition of gasoline. 

7 INDIGO CARMINE, AMARANTH AND TARTRAZINE. 

The presence of 2 or all 3 of these dyes is usually indicated by the appearance 
of the N/4 hydrochloric acid washings, B, under 5. Evaporate the combined N/4 
hydrochloric acid washings to dryness to remove the excess of hj'drochloric acid and 
dissolved amyl alcohol. Dissolve the residue in water, divide the solution and iden- 
tify the constituent colors in the portions. To a portion of the slightly acidified 
solution add a few decigrams of urea, warm and add 1 or 2 drops of sodium nitrite 
solution. Indigo Carmine is converted into the pale yellow isatin sulphonate while 
the other dyes are but little affected. The isatin compound is not ordinarily present 
in sufficient concentration to tint the solution but it differs from Tartrazine also in 
being much less readily extracted by amyl alcohol from strong acid solutions (less 
than one half from 4N acid). The solution now contains the Amaranth or Tar- 
trazine, or both, practically unaffected. Amaranth is much more quickly attacked 
by most reducing agents than Tartrazine. Treat the solution, which should be neu- 
tral or faintly acid (in the presence of sodium carbonate the reduction of the tar- 
trazine takes place still more slowly), at room temperature with a dilute solution of 
sodium hyposulphite (Na2S204), adding the latter very carefully, drop by drop, and 
allowing sufficient time after the addition of each drop for the reduction to take 
place. When the color shows that the Amaranth has been destroyed completely, 
shake the mixture at once with air to oxidize the slight excess of hyposulphite before 
it can react further on the Tartrazine. 

To separate the Indigo Carmine heat to boiling another portion of the solution, 
which should be neutral or faintly acid, and add dilute sodium h,yposulphite solution, 
drop by drop, until all the dyes are reduced. On shaking with air the Indigo Carmine 
is quickly re-formed. 

8 NAPHTHOL YELLOW S AND PONCEAU 3R. 

Treat the N/4 acid solution or the salt solution, C, under 6, as the case may be, 
containing the Ponceau and Naphthol Yellow S, with enough hydrochloric acid to 
make it about 2N and shake out a few times with washed ethyl acetate*. Remove 



XI] COLORING MATTERS IN FOODS 159 

the Yellow from the combined ethyl acetate extracts by shaking with water. Naph- 
thol Yellow S is almost colorless in strongly acid solutions, and its absence in wash- 
ings, etc., must never be assumed until these have been made alkaline. Finally 
separate the Ponceau 3R from the acid solution by shaking with amyl alcohol, and 
then wash out the dye from this extract with a few small portions of water. If, 
in the case of mixtures containing Orange I, the washings of the ethyl acetate, which 
should contain only Naphthol Yellow S, become more red upon the addition of al- 
kalies, combine, then (1) Make N/4 with hydrochloric acid and remove the contami- 
nating Orange by shaking with amyl alcohol-gasoline mixture (1 to 1); or, (2) Treat 
the combined washings with one fifth their volume of concentrated hydrochloric 
acid, extract the dyes by shaking once with amyl alcohol, and remove the Yellow 
by washing with several portions of 5% salt solution. 

9 LIGHT GREEN S F YELLOWISH. 

The original mixture, A, under 5, from which the above mentioned 7 colors have 
been removed by adding acid and shaking out with amyl alcohol, may still contain 
Light Green S F Yellowish, which will be colorless or nearly so in the acid solution. 
To separate this dye treat the mixture with strong ammonia or potassium hydrox- 
id solution until slightly alkaline, and neutralize with acetic acid. Any Green 
present will now be apparent by the color of the mixture. Extract the color by 
shaking with a few small portions of dichlorhydrin. Wash the dichlorhydrin extract 
with a little water, then dilute with several volumes of benzene or carbon tetra- 
chlorid, and remove the dye by shaking with water. 

When coal tar dyes other than the 8 mentioned above are present, the solutions 
obtained in this procedure will be found to contain a coloring matter which does not 
correspond exactly in properties to one of the dyes named above. When coal tar 
dyes other than these 8 are present, reference should be made to the larger works'. 

Coal Tar Dyes in General. 

10 basic dyes. 

Most basic dyes may be separated from mixtures by making alkaline with sodium 
hydroxid and shaking with ethex'". Use the sample, prepared as in 4, for this pur- 
pose. Separate the ether layer, which may or may not be colored, and shake with 
2-5% acetic acid, which will take up any dye present, forming a colored solution. 
Although the common basic colors undergo some alteration by this treatment^S 
it may be used for the qualitative detection and separation of Methyl Violet B (451), 
Magenta (448), Bismarck Brown (197), Malachite Green (4^7), and Rhodamine B 
(504). With care Auramine (425) may also be separated in this way though it is 
quickly decomposed on standing in alkaline solution. 

11 ACID DYES. 

The following short procedure is often convenient for the examination of mixtures 
of acid dyes: Make the sample, prepared as in 4, the color concentration of which 
does not vary greatly from 0.01-0.05%, strongly acid by adding one half its volume 
of concentrated hydrochloric acid and shake with amyl alcohol. Separate the 
amyl alcohol solution and wash by shaking with successive portions of one half its 
volume of water, reserving the portions in separate test tubes or beakers. Because 
of the acid dissolved in the amyl alcohol these washings will show a regular decrease 
in acidity and the coloring matters will appear in maximum amount in the different 
fractions according to their respective solubilities. Ponceau 6R (108) is washed 
out chiefly while the acidity is still high, N/1 or above. Amaranth (107), Brilliant 



160 METHODS OF ANALYSIS [Chap. 

Scarlet (106) and Tartrazine (94) appear when the washings have an acidity between 
N/1 and N/4; Orange G (14) and Soluble Blue (480) between N/2 and N/16; Palatine 
Scarlet (53), Ponceau 2R (55) and 3R (56), Naphthol Yellow S (4), Cochineal (706), 
Crystal Ponceau (64) and Azorubine A (103) between N/16 and N/256. When the acid 
is practically all removed, Orange I (85), Orange II (88) and Croceine Orange (13) 
begin to wash out, and less readily. Orange IV (88) and Metanil Yellow (95). Finally 
the unsulphonated coloring matters, such as Erythrosine G (516), Erythrosine (517) 
and the Rose Bengals (520 and 523) are removed very slowly by water or not at all 
when all traces of acid have been removed. Acid Yellow (8) and Brilliant Yellow 
S (89) are not very uniform in composition. They are partially taken up by amyl 
alcohol from acid solution and appear chiefly in the first washings. Indigo Carmine 
(692) behaves somewhat similarly. 

Identification of the Coal Tar Dyesi2. 

12 GENERAL. 

The most widely used tests for the identification of coal tar dyes refer to the 
changes produced with acids and alkalies. Other tests, based upon the behavior 
with reducing agents, followed perhaps by treatment with oxidants or by separation 
and identification of the reduction products^', and tests based upon oxidation of the 
dye and treatment of the oxidation products'* are generally applicable. Spectro- 
scopic methods are also used'^. 

13 COLOR CHANGES PRODUCED WITH ACIDS AND ALKALIES. 

Transfer the separated coloring matter to wool (or silk in the case of oil-soluble 
dyes) by boiling as directed in 2 (a) or 3. Care should be taken that the final dyeing 
is made in a solution fairly free from foreign matter such as sugar or aromatic sub- 
stances, which, adhering to the fiber, may modify the reaction. In most cases the 
amount of color available is small and should not be dyed on too large a piece of wool 
(or silk). Rinse thoroughly the dyed fibre in running water, dry, cut into small pieces 
and place separately in the depressions of a white porcelain spot plate. Moisten the 
pieces with the respective reagents employed. (For many coloring matters the 
hue upon treatment with acids or alkalies varies markedly with the concentration 
of the reagents and amount of dye present; therefore the unknown dye should be 
compared with dyeings of known colors of approximately the same dye concentration 
as shown by this appearance.) 

The table under 14 shows the color changes produced by concentrated hydro- 
chloric and sulphuric acids, 10% sodium hydroxid and 12% ammonium hydroxid 
solutions on wool dyed with 0.1-0.5% of the respective coloring matters. Included 
also are the reactions of the oil-soluble colors but these refer to dyeings on silk. 
The dyes are arranged approximately according to hue. Brown is classed with 
orange, black (gray) with violet. 



XI] 



COLORING MATTERS IN FOODS 



161 



14 



Table 14. 
Color reactions produced on dyed fibers by various reagents. 







HYDROCHLORIC 






AMMONIUM 


COLORING MATTER 




ACID 


SULPHURIC ACID 


SODIUM HYDHOXID 


HYDROXID 


Rhodamine B 


504 


Orange 


Yellow 


Bluer 


Bluer 


Rose Bengal 


523 


Almost 


Orange 


No change 


No change 




decolorized 








Archil 


710 


Red 


Dull brown 


Violet 


Violet 


Magenta 


US 


Yellowish 
brown 


Dull brown 


Decolorized 


Paler 


Acid Magenta 


m 


Almost 
decolorized 


Yellow 


Decolorized 


Decolorized 


Piilatine Red 


62 


Darker 


Violet 


Dull brown 


Little change 


Bordeaux B 


65 


Violet 


Blue 


Brown 


Little change 


Amaranth 


107 


Slightly 


Violet to 


Dull brown- 


Little change 






darker 


brownish 


ish 




Azorubine A 


lOS 


Little change 


Violet 


Red 


Red 


Erythrosine 


517 


Orange-yellow 


Orange-yellow 


No change 


No change 


Ponceau 6RB 


169 


Blue 


Blue 


Dull violet- 
red 
Brown 


Little change 


Ponceau 6R 


108 


Violet-red 


Violet 


Orange-red 


Crystal 


64 


Violet-red 


Violet 


Dull brown 


Little change 


Ponceau 












Ponceau 3R 


56 


Little change 


Little change 


Dull orange 


Little change 


Sudan 111* 


US 


Violet, then 

brown 
Greenish blue 


Green 


Violet-red 


Little change 


Safranine 


584 


Green 


Red 


Red 


Brilliant 


106 


Red 


Violet-red 


Yellowish 


Orange-red 


Scarlet 








brown 




Ponceau 2R 


55 


Little change 


Little change 


Brownish 
yellow 


No change 


Palatine 


53 


Darker 


Violet-red 


Brownish 


No change 


Scarlet 








yellow 




Erythrosine G 


516 


Yellow-orange 


Yellow-orange 


No change 


No change 


Sudan 11* 


49 


Red 


Violet-red 


Little change 


No change 


Sudan 1* 


11 


Orange-red 


Red 


Redder 


No change 


Cochineal 


706 


Little change 


Little change 


Violet-red 


Violet-red 


Bismarck 


197 


Redder, 


Browner 


Yellower 


Yellower 


Brown 




darker 








Bismarck 


201 


Redder, 


Browner 


Yellower 


Yellower 


Brown R 




darker 








Orange I 


85 


Violet 


Violet 


Red, dark 


Red, dark 


Orange 11 


86 


Red 


Red 


Dull red 


No change 


Croceine 


IS 


Orange-red 


Orange 


Slightly 


No change 


Orange 








darker 




Orange G 


14 


Little change 


Orange 


Dull, brown- 
ish red 


No change 


Orthotoluene- 




Red 


Violet 


Little change 


No change 


azo-beta- 












naphthyl- 












amine* 












Sudan G* 


10 


Orange-yellow 


Brownish 
yellow 


Orange-yellow 


No change 


Butter Yellow* 


16 


Violet-red 


Orange-yellow 


No change 


No change 


Aniline Yellow* 


7 


Brownish red 


Orange-yellow 


Little change 


No change 


Aminoazo- 




Dull orange 


Orange-yellow 


Little change 


No change 


ortho-tolu- 












ene* 













Oil-soluble. 



162 



METHODS OF ANALYSIS 



[Chap. 



14 



Table 14. — Continued. 



COLORING MATTER 




HYDROCHLORIC 
ACID 


SULPHURIC ACID 


SODIUM HYDROXID 


AMMONIUM 
HYDROXID 


Fluoresceine 


510 


Little change 


Little change 


Green flu- 
orescent 


Green flu- 
orescent 


Metanil Yellow 


95 


Violet-red 


Violet 


No change 


No change 


Azoflavine 


92 


Violet-red 


Violet-red 


Dull brown 


Little change 


Acid Yellow 


8 


Red 


Orange 


Little change 


No change 


Brilliant 


89 


Violet-red 


Violet-red 


Little change 


Little change 


Yellow S 












Tartrazine 


94 


Slightly 
darker 


Slightly 
darker 


Little change 


Little change 


Naphthol 


4 


Almost 


Very pale, 


No change 


No change 


Yellow S 




decolorized 


dull brown 






Auramine 


m 


Decolorized 


Almost 

decolorized 


Decolorized 


Paler 


Turmeric 


707 


Red 


Reddish 
brown 


Orange 


Orange 


Quinoline 


667 


Slightly 


Brownish 


Slightly 


Little change 


Yellow 




darker 


yellow 


paler 




Naphthol 


398 


Yellowish 


Brownish 


No change 


No change 


Green B 






yellow 






Guinea Green 


4SS 


Pale orange- 


Pale, dull 


Decolorized 


Decolorized 


B 




yellow 


yellow 






Light Green SF 


435 


Pale orange- 


Pale, dull 


Decolorized 


Decolorized 


Yellowish 




yellow 


yellow 






Night Green 2B 


438 


Pale orange- 
yellow 


Pale, dull 
yellow 


Decolorized 


Paler 


Malachite 


427 


Almost 


Almost 


Decolorized 


Decolorized 


Green 




decolorized 


decolorized 






Erioglaucine A 


436 


Yellow 


Pale, dull 
yellow or 
brown 


Slightly 
darker 


Little change 


Patent Blue A 


442 


Pale orange- 
vellow 


Pale or dull 
brown 


Little change 


Little change 


Soluble Blue 


480 


Paler 


Brown 


Pale reddish 


Almost decol- 
orized 


Indigo Carmine 


692 


Slightly 


Slightly 


Greenish yel- 


Greenish blue 






darker 


darker 


low 




Formyl Violet 


468 


Pale orange- 
yellow 


Pale, dull 
orange 


Decolorized 


Decolorized 


Methyl Violet B 


451 


Yellowish 


Yellowish 


Decolorized 


Almost decol- 
orized 


Nigrosine, sol- 


602 


Dull bluish 


Dull greenish 


Brownish red. 


Pale reddish 


uble 








paler - 





15 SPECIAL TESTS FOR COAL TAR DYES PERMITTED^ UNDER THE FEDERAL 

FOOD AND DRUGS ACT. 

The dyes, given in 5, are sufficiently characterized in most cases by the solubilities 
shown in their separation and by the color changes given by acids and alka'ies on 
the dyed fiber. This is especially true with Amaranth, Tartrazine, and Orange I. 
By treatment with reducing agents such as stannous chlorid, titanous chlorid, zinc 
dust or sodium hyposulphite in acid solution, Indigo Carmine, Amaranth, Tartra- 
zine, Ponceau 3R and Orange I are decolorized. With Indigo Carmine the color 
returns on shaking with air, most readily on warming, or on the addition of oxidiz- 
ing agents such as ferric chlorid or potassium persulphate. Excess of the reducing 
agents must of course be avoided. With the last 4 named dyes the color is not re- 
stored. Dilute solutions of Light Green S F Yellowish, Naphthol Yellow S and 



XI] COLORING MATTERS IN FOODS 163 

Erythrosine become paler or colorless with acids so that the effects of acid reducing 
agents are not so readily apparent. Neutral solutions of Naphthol Yellow S are 
decolorized by sodium hyposulphite and other reducing agents, the color not return- 
ing with air or oxidants. An evanescent deepening of the shade may take place 
immediately upon the addition of the hyposulphite. Erythrosine and Light Green 
S F Yellowish become paler with sodium hyposulphite, the color being partially 
restored upon the addition of potassium persulphate. 

In hot solutions containing an excess of sodium tartrate the dyes named 
are readily decolorized by titanium trichlorid^^ In the case of Indigo Carmine if 
the reducing agent has been added carefully and an excess avoided, the blue color 
readily returns on shaking with air. With Erythrosine and Light Green S F Yel- 
lowish the color is scarcely restored by air but on cooling and adding potassium 
persulphate returns imperfectly. The reduction products of the other dyes do 
not give colored solutions again on oxidation disregarding a slight yellowish or 
brownish tint that may sometimes appear. 

Indigo Carmine is extracted in small proportions from slightly acid solutions by 
shaking with dichlorhydrin. Most of the other common bluish dyes are triphenyl- 
methane derivatives and are relatively more soluble in this liquid than in the aque- 
ous layer. A small portion (1 cc.) of the solution obtained in the separation, 5, 
may be used directly. 

Ponceau 3R gives in neutral or faintly acid solutions a bluish red, flocculent pre- 
cipitate with barium chlorid or acetate, practically all of the dye being removed from 
solution. Some of the solution obtained in the separation, 5, may be used in this 
test, first neutralizing the free hydrochloric acid with sodium acetate; or better, it 
may be evaporated to dryness on the steam bath to remove the acid and the residue 
taken up with a little water. The solution should contain 0.005% or more of the 
dye. 

Naphthol Yellow S, in solutions containing an excess of ammonia or sodium car- 
bonate, becomes intensely rose-red on the addition of sodium hyposulphite, the color 
gradually fading again as complete reduction takes place. 

Erythrosine differs from most of the common dyes by containing iodin. To test 
for this, acidify the solution with sulphuric acid, shake with ether, separate the 
ether solution of the color and evaporate to dryness in a platinum dish after the 
addition of a few drops of sodium carbonate solution or sufficient to form the deep 
red sodium salt. Hold the dish containing the residue in the Bunsen flame until 
organic matter is destroyed, take up the residue with water, acidify with sulphuric 
acid and test for iodin in one of the usual ways, such as with chlorin water and carbon 
disulphid or tetrachlorid, or with starch paste and an oxidizing agent. It is useless 
to test for iodin with very small amounts of dye but in most cases sufficient coloring 
matter can be separated from the food product to give satisfactory results. 

16 Natural Coloring Matters. 

The natural coloring matters as a class show much less tendency to dye animal 
fiber than do the common synthetic colors. In many cases the crude products used 
contain a number of colored substances and a complete separation can scarcely be 
attempted. Most of the natural coloring matters, in dilute solution, are sensitive 
to alkalies, some to acids, hence such reagents must be used with care. 



164 METHODS OF ANALYSIS [Chap. 

SEPARATION OF NATURAL COLORING MATTERS. 

1 7 Extraction with Ether from Neutral Solutions. 

From neutral solutions ether extracts Carotin, Xanthophyll (the pigment found in 
leaves, fats and oils, egg yolk, carrots, etc.), the coloring matter of tomatoes and 
paprika and green Chlorophyll. The coloring matter remains in the ether solution 
on shaking with dilute sodium hydroxid solution or dilute hydrochloric acid, no 
apparent change taking place although chemically the substances may be altered 
more or less by this treatment. 

18 Extraction with Ether from Acid Solutions, 

From slightly acid solutions ether extracts very readily and completely the 
coloring matter of Alkanet, Annatto, Turmeric, and the red dyewoods. Sandalwood, 
Camwood and Barwood. It extracts in large proportion the flavone coloring matters 
of Fustic, Persian Berries (after hydrolysis), and Quercitron as well as the coloring 
matter of Brazilwood and the green derivatives formed from Chlorophyll by alkaline 
treatment. It extracts in relatively small amount the coloring matters of Logwood, 
Archil, Saffron and Cochineal. The coloring matters of this group are readily re- 
moved from ether by shaking with alkaline solutions but in most cases rapidly 
undergo chemical change. 

19 Extraction with Aviyl Alcohol from Acid Solutions. 

From slightly acid solutions amyl alcohol extracts largely the coloring matters of 
Logwood, Archil, Saffron and Cochineal. [From ammoniacal Cochineal (Carmine) 
the ordinary coloring matter is readily re-formed upon standing with hydrochloric 
acid.] Amyl alcohol extracts in relatively small proportions Caramel and the Antho- 
cyans constituting the red coloring matter of the most common fruits. 



20 



IDENTIFICATION OF NATURAL COLORING MATTERS. 

REAGENTS. 



(a) Hydrochloric acid. — Sp, gr. L20. 

(b) 10% sodium or potassium hydroxid solution. 

(C) Sodium hyposulphite solution. — A freshly prepared 5% solution of "Blankite", 
sodium hyposulphite (Na2S204). 

(d) 0.5% ferric chlorid solution. — Freshly prepared but may be made by diluting a 
10% stock solution. 

(e) 10% potassiu7n or ammonium alum solution. 

(f ) 5% uranium or sodium uranium acetate solution 
(^) Sulphuric acid. — Sp. gr. L84. 



21 



PROCEDURE. 



Relatively few good tests are known for the common natural colors. Some of 
their most useful analytical properties'^ are tabulated in 22. In general these tests 
should be applied to the somewhat purified solutions of the coloring matter obtained 
as indicated in 17, 18 or 19. 

Evaporate ether solutions to dryness, warm the residue with a little alcohol and 
dilute the alcoholic solution with water. Apply the reagents as stated below: 



XI] COLORING MATTERS IN FOODS 165 

Hydrochloric acid. — Add concentrated acid (sp. gr. 1.20) to the solution, first 
1 or 2 drops, then a large excess, equal to 3-4 times the volume of the solution. 

Sodium hydroxid {potassium hydroxid). — Make the solution slightly alkaline by 
adding a drop of the 10% sodium hydroxid solution. A 10% solution of potassium 
hydroxid in methyl alcohol must be used for the "brown phase reaction" for chloro- 
phyll, described in 23, and may also be employed for the other tests. 

Sodium hyposulphite. — Add the sodium hyposulphite solution drop by drop. 

Ferric chlorid. — Add a small amount of the 0.5% ferric chlorid solution to the 
solution to be tested. The reagent must be added very carefully, a small drop at a 
time, as the colorations are not obtained in all cases when an excess is used. 

Alum. — Add to the test solution one fifth its volume of the 10% potassium or 
ammonium alum solution. 

Uranium acetate. — Add the 5% uranium acetate solution drop by drop to the solu- 
tion to be tested. 

Concentrated sulphuric acid on the dry color. — Evaporate a small amount of the 
solution or of the coloring matter in a porcelain dish. Cool thoroughly and treat 
the dry residue with 1 or 2 drops of cold, concentrated sulphuric acid. The color- 
ations are in some cases extremely fugitive and may be observed only the instant 
the acid wets the residue. 

The properties of pure preparations of the various natural coloring matters are 
described, for the most part, by Rupe*^. Properties of the Chlorophylls and 
Carotinoids are given by Yv'illstatter and Stoll'". Those of the coloring matters of 
the Corn Flower, Rose, Pelargona Flower, Larkspur, Cranberry, Whortleberry and 
Purple Grape are described by Willstatter^o. 



166 



METHODS OF ANALYSIS 



[Chap. 



B O (g 

5 2 O 

5 •* hJ 

S o o 

6 M O 

5 « !x 

w I-, ?< 

^ S 






73 O 



P^ 



> > 



'3 

QJTS 



^ 0) 
O tt) 



M O c3 , — I 



o a S '-N 

{/} O 03 <— I 
O v^ tH CO 

Pi 






03 f> 



2 o O 






ml)—. 



5 > 



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s w S 



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cu 


+i 


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n 






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Ph 



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XIJ 



COLOEING MATTERS IN FOODS 



167 



m 



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a 



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1-1 










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168 METHODS OF ANALYSIS [Chap. 

Special Tests for Natural Coloring Matters. 

23 chlorophyll. 

The "brown phase reaction"^' may be useful for the characterization of Chloro- 
phyll, when this has not been previously treated with alkalies. Treat the green 
ether or petroleum ether solution of the coloring matter with a small amount of 
10% solution of potassium hydroxid in methyl alcohol. The color becomes brown, 
returning to green in a few minutes. 

ANNATTO. 

24 Leach Tesf-K 

Pour on a moistened filter an alkaline solution of the color obtained by shaking out 
the oil or melted and filtered fat with warm, dilute sodium hydroxid solution. If 
Annatto is present, the filter paper will absorb the color so that, when washed with 
a gentle stream of water, it will remain dyed a straw color. Dry the filter and add a 
drop of stannous chlorid solution. If the color turns pink the presence of Annatto 
is confirmed. 

25 TURMERIC. 

Carry out the highly characteristic reaction of Curcumine (Turmeric) with boric 
acid as follows: Treat the aqueous or dilute alcoholic solution of the color with 
hydrochloric acid until the shade just begins to appear slightly orange. Divide 
the mixture into 2 parts and add some boric acid powder or crystals to 1 portion. 
A marked reddening will be quickly apparent, best seen by comparison with the 
portion to which the boric acid has not been added. The test may also be made by 
dipping a piece of filter paper in the alcoholic solution of the coloring matter, drying 
at 100°C., then moistening with a weak solution of boric acid to which a few drops 
of hydrochloric acid have been added. On drying again a cherry-red color will be 
developed. 

26 COCHINEAL. 

When the presence of Cochineal is suspected, acidify the mixture with one third 
its volume of concentrated hydrochloric acid and shake with amyl alcohol. Wash 
the amyl alcohol solution of the coloring matter 2-4 times with equal volumes of 
water to remove hydrochloric acid, etc. Dilute the amyl alcohol with 1-2 volumes of 
gasoline and shake with a few small portions of water to remove the color. Sepa- 
rate the solution into 2 portions. To the first add, drop by drop, 5% uranium ace- 
tate solution, shaking thoroughly after each addition. In the presence of cochineal 
a characteristic emerald-green color is produced^^ The green coloration with 
uranium salts is not developed in the presence of much free acid. Therefore add a 
little sodium acetate before making this test or a correspondingly large amount of 
uranium acetate must be added. To the second portion add a drop or so of ammon- 
ium hydroxid, and, in the presence of Cochineal, a violet coloration results. This, 
however, is not so sensitive to small amounts as the first test and many fruit colors 
give tests hardly to be distinguished. 

As cochineal lakes very often contain tin, further examination for this metal 
should always be made when water-insoluble cochineal compounds appear to be 
present. 



XI] COLORING MATTERS IN FOODS 169 

BIBLIOGRAPHY. 

' Schultz. Farbstofftabellen. .5th German ed., 1911-14. 

2Abs. Z. anal. Chem., 1885, 24: 625; 1889, 28: 639; Conn. Agr. Exp. Sta. Kept., 
1899, (11), p. 130. 

3 J. Am. Chem. Soc., 1905, 27: 25. 

* Abs. Z. anal. Chem., 1896, 35: 397. 

^U. S. Bur. Chem. Bull. 65, p. 152; Ann. fals., 1910, 3: 293; U. S. Bur. Chem. 
Circs. 25 and 63; Abs. Chem. Zentr., 1898, (2), 943. 

^ U. S. Bur. Chem. Circs. 25 and 63; Allen. Commercial Organic Analj'sis. 4th 
ed., 1909-14, 5; Leach. Food Inspection and Analysis. 3rd ed., 1913; Girard and 
Dupre. Analyse des Malieres Alimentaires et Recherches de leur Falsification. 1894; 
J. pharm. chim., 6th ser., 1901, 13: 175; U. S. Bur. Animal Industry Circ. 180. 

' U. S. Dept. Agr., F. I. Ds. 76 and 164. 

8 U. S. Bur. Chem. Bull. 162, p. 57. 

*Heumann. Die Anilinfarben und ihre Fabrikation. 1888-1906; Green. Sys- 
tematic Survey of the Organic Colouring Matters. 2nd ed., rev., 1904, based on the 
German of Schultz and Julius; Schultz. Farbstofftabellen. 5th German ed., 1911- 
14; Allen. Commercial Organic Analysis. 4th ed., 1909-14, 6; MuUiken. Identifi- 
cation of Pure Organic Compounds. 1910, 3. 

10 Abs. Z. anal. Chem., 1887, 26: 100; 1888, 27: 232. 

"Ber., 1913, 46: 2131; 1914, 47: 1881. 

12 Abs. Z. anal. Chem., 1887, 26: 100; 1888, 27: 232; Chem. Ztg., 1898, 22: 437; 
U.S. Bur. Chem. Circ. 63; Green. The Identification of Dyestuffs on Animal Fibres. 
Rev. ed., 1913. 

I'Ber., 1888, 21: 3471. 

» U. S. Bur. Chem. Circ. 114. 

i^Form^nek. Spektralanalytischer Nachweiss kiJnstlicher Organischer Farb- 
stoffe zum Gebrauche bei wissenschaftlichen und gewerblichen Untersuchungen. 
1900; Formdnek und Grandmougin. Untersuchung und Nachweiss Organischer 
Farbstoffe auf Spectroskopischem Wege. 2nd ed., 1908-13. 

I"' Knecht and Hibbert. New Reduction Methods in Volumetric Analysis. 1910. 

1^ U. S. Bur. Chem. Circs. 25 and 63; Allen. Commercial Organic Analysis. 4th 
ed., 1909-14, 5; Leach. Food Inspection and Analysis. 3rd ed., 1913. 

i» Rupe. Die Chemie der Natijrlichen Farbstoffe. 1900-09. 

1' Willstatter and Stoll. Untersuchungen iiber Chlorophyll, Methoden und 
Ergebnisse. 1913. 

^oSitz. preuss. Akad., 1914, 12: 402. 

" Ber. botan. Ges., 1896, 14: 16; Willstatter and StoU. Untersuchungen Uber 
Chlorophyll, Methoden und Ergebnisse. 1913. 

"^^ Leach. Food Inspection and Analysis. 3rd ed., 1913, p. 536. 

^^ Girard and Dupre. Analyse des Matieres Alimentaires et Recherches de leur 
Falsification. 1894. 



1 



XII. METALS IN FOODS. 
ARSENIC 1 .—TENTATIVE . 

REAGENTS. 



(a) Nitric and sulphuric acids, arsenic-free. — Specific gravities 1.42 and 1.84, 
respectively. 

(b) Sulphuric acid (1 to 2). 

(C) Zinc, arsenic-free. — Stick zinc broken into pieces approximately 1 cm. in 
length. 

(d) Lead acetate paper. — Heavy filter paper soaked in 20% lead acetate solution, 
dried and cut into pieces about 4.5 by 16 cm. 

(e) Lead acetate cotton. — Absorbent cotton soaked in 5% lead acetate solution. 

(f) Mercuric hrornid paper. — Cut heavy, close-textured drafting paper (similar 
to Whatman's cold pressed) into strips exactly 2.5 mm. wide and about 12 cm. long. 
Soak for an hour in a 5% solution of mercuric bromid in 95% alcohol, squeeze out 
the excess of solution and dry on glass rods. Cut off the ends of the strips before 
using. 

(6) ^0% potassium iodid solution. 

(h) Stannous chlorid solution. — Forty grams of stannous chlorid crystals made up 
to 100 cc. with concentrated hydrochloric acid. 

(i) Standard arsenic solution. — Dissolve 1 gram of arsenious oxid in 25 cc. of 20% 
sodium hydroxid solution, neutralize with dilute sulphuric acid, add 10 cc. of the 
concentrated sulphuric acid and dilute to 1 liter with recently boiled water. One 
cc. of this solution contains 1 mg. of arsenious oxid (AS2O3). 

Dilute 20 cc. of this solution to 1 liter. Fifty cc. of the latter solution when 
diluted to 1 liter give a dilute standard solution containing 0.001 mg. of arsenious 
oxid (AS2O3) per cc. which is used to prepare the standard stains. The dilute solu- 
tions must be freshly prepared immediately before use. 

2 APPARATUS. 

Use a 2 ounce wide-mouthed bottle as a generator. Fit this by means of a per- 
forated rubber stopper with a glass tube, diameter 1 cm. and 6 cm. long, containing 
a piece of the lead acetate paper rolled into a cylinder. Connect this tube by means 
of a perforated rubber stopper with a similar tube filled with the lead acetate cotton, 
squeezed to remove excess of the solution. The cotton in all tubes used should be 
uniformly moist to obtain comparative stains. Connect the second tube by means 
of a perforated rubber stopper with a narrow glass tube, internal diameter 3 mm. 
and 12 cm. long, containing a strip of the mercuric bromid paper. See Fig. 7. Rubber 
stoppers used for connections must be free from any white coating. 

3 PREPARATION OF SOLUTION. 

Weigh 5-50 grams of the finely divided and well mixed sample into a porcelain 
casserole, the amount selected depending upon the character of the material and the 
ease with which it is oxidized. With dry, highly nitrogenous substances employ 
5 grams; pulped vegetables, 25 grams; liquids with low solid content like beer or 

171 



172 



METHODS OF ANALYSIS 



[Chap. 



vinegar, 50 grams. Add 10-15 cc. of the nitric acid, cover the casserole by setting 
a watch glass inside the rim, convex side upward, heat until vigorous action is 
over, cool and add 10 cc. of the concentrated sulphuric acid. Heat on a wire gauze 
over a flame until the mixture turns dark brown or black, then add more nitric acid 
in 5 cc. portions, heating between each addition until the liquid remains colorless 
or yellow when evaporated until sulphur trioxid fumes are evolved. To remove 



FIG. 7. APPARATUS FOR THE DETERMINATION OF ARSENIC. 

completely all nitric or nitrous acid, evaporate to about 5 cc, cool, dilute with 10- 
15 cc. of water and again evaporate until white fumes are evolved. Cool, dilute with 
water, again cool, and make up with water to a definite volume (usually 25-100 cc, 
depending upon the amount of sample taken and its arsenic content). 



DETERMINATION. 



Introduce 20 cc. of the solution or, if the amount of arsenic is large, an aliquot 
containing not more than 0.03 mg. of AsjOa, prepared as directed in 3, into th« 



XII] METALS IN FOODS 173 

generator of the apparatus described in 2 and add 20 cc. of the dilute sulphuric acid. 
If the total volume is less than 40 cc, dilute to that volume with water and add 

4 cc. of the 20% potassium iodid solution. Heat to about 90°C., add 3 drops of 
the stannous chlorid solution and heat for 10 minutes. Cool the generator and its 
contents in a pan containing water and ice; when cold add about 15 grams of the 
stick zinc and connect the entire apparatus as described in 2. Keep the bottles in 
ice water for 15 minutes, then remove from the bath and allow the evolution of gas 
to proceed for an hour longer. Remove the sensitized paper and compare the stain 
with similar ones produced under like conditions with known amounts of arsenic, 
using portions of the standard arsenic solution, containing 0.001, 0.002, 0.005, 0.010, 
0.015, 0.025 and 0.030 mg. of arsenious oxid (AS2O3), and adding such quantities of 
water and sulphuric acid that the same volume and acid strength are maintained as 
above. 

TIN''. 

5 Gravimetric Method. — Tentative. 

Weigh 50-100 grams of the sample (depending upon the amount of dry substance 
present and the relative ease with which the organic matter is oxidized) into an 800 
cc. Kjeldahl flask and add 100 cc. of concentrated nitric acid. Allow to stand over- 
night (this procedure being preferred if much fat or sugar is present) or else place 
the flask on a wire gauze over a free flame and heat until the contents boil quietly. 
Add 25-50 cc. of concentrated sulphuric acid (depending upon the amount of dry 
substance present in the sample), and heat until white fumes are generated, cool 
somewhat, then add 5-10 cc. of concentrated nitric acid and continue heating as 
before. Repeat the addition of nitric acid until the solution remains clear after 
boiling off the nitric acid and fumes of sulphur trioxid appear. 

Add 200 cc. of water to the digested sample, prepared as directed above, and pour 
into a 600 cc. beaker. Rinse out the Kjeldahl flask with 3 portions of boiling water 
so that the total volume of the solution is about 400 cc. Cool, add concentrated 
ammonia until just alkaline and then hydrochloric or sulphuric acid until the acidity 
is about 2%. Place the beaker, covered, on a hot plate, heat to about 95''C. and pass 
in a slow stream of hydrogen sulphid for another hour. Digest on the hot plate for an 
hour and allow to stand 1-2 hours longer. 

Filter the tin sulphid on an 11 cm. filter, similar in quality to No. 590, white ribbon, 
S. & S. Wash alternately with 3 portions each of wash solution (100 cc. of saturated 
ammonium acetate solution, 50 cc. of glacial acetic acid and 850 cc. of water) and 
hot water. Digest the filter and precipitate in a 50 cc. beaker with 3 successive 
portions of ammonium polysulphid, heat to boiling each time and filter through a 
9 cm. filter. Wash the precipitate on the filter with hot water. Acidify the filtrate 
with acetic acid, digest on a hot plate for an hour, allow to stand overnight and 
filter through a double 11 cm. filter. Wash alternately with 2 portions each of the 
wash solution and hot water and dry thoroughly in a weighed porcelain crucible. 
Ignite over a Bunsen flame, very gently at first and later at full heat. The cru- 
cible, partly covered, is then heated strongly with a large or Meker burner. Stan- 
nic sulphid must be roasted gently to the oxid, which may be heated strongly with- 
out loss by volatilization. Weigh as stannic oxid and calculate to metallic tin. 

Volumetric Method^. — Tentative. 

6 REAGENTS. 

(a) Air-free wash solution. — Dissolve 20 grams of sodium bicarbonate in 2 liters 
of boiled water and add 40 cc. of concentrated hydrochloric acid. This solution 
should be freshly prepared before use. 



174 METHODS OF ANALYSIS [Chap. 

(b) N/lOO iodin. — The solution must be standardized frequently against (d), con- 
taining asbestos, and treated as described in 7, omitting the precipitation and boil- 
ing with hydrochloric acid and potassium chlorate. To obtain exact results the 
tin solution used for standardization should contain about the same amount of tin 
as is found in the sample under examination. 

(C) N/100 sodium thiosulphate . 

(d) Standard tin solution. — Dissolve 1 gram of tin in about 500 cc. of concen- 
trated hydrochloric acid. Make up to 1 liter with water. One cc. contains 1 mg. 
of tin. 

(e) Sheet aluminium. — Use sheet aluminium, about 30 gauge, free from tin. 

7 DETERMINATION. 

Proceed as directed in 5 to "Digest on the hot plate for an hour and allow to 
stand 1-2 hours longer". 

Filter the precipitate of tin sulphid upon asbestos in a Gooch crucible with a 
detachable bottom, using suction. Wash the precipitate a few times and then 
transfer the detachable bottom, asbestos pad, and tin precipitate to a 300 cc. Er- 
lenmeyer flask. Remove all traces of the precipitate from the inside of the cru- 
cible by means of a jet of hot water and a policeman, using a minimum amount of 
water for washing. 

Add 100 cc. of concentrated hydrochloric acid and 0.5 gram of potassium chlorate 
to the flask. Boil for about 15 minutes, making about 4 more additions of smaller 
amounts of potassium chlorate as chlorin is boiled out of the solution. Wash the 
particles of potassium chlorate down from the neck of the flask with water and 
finally boil to remove chlorin. Then add about 1 gram of the sheet aluminium to 
dispel the last traces of chlorin. 

Attach the flasks, in duplicate, as described below, to a large carbon dioxid gener- 
ator. Pass the carbon dioxid through a scrubber containing water and then divide 
into 2 streams by means of a Y-tube, each stream of carbon dioxid entering one of 
the flasks by means of a long rubber tube connected with a bulbed tube, passed 
through the rubber stopper of the flask and having its lower end near the surface of 
the liquid in the flask. The carbon dioxid leaves the flask by a second bulbed tube, 
the opening of which is near the top of the flask. This glass tube is connected by a 
long rubber tube to a second glass tube about 10 inches long which is immersed in a 
cylinder containing water. This gives a water-seal to the delivery tube and a pres- 
sure against which the current of carbon dioxid must work. It also restrains any 
strong flow of gas when not desired and permits a gas pressure in the Erlenmeyer 
flask. 

After the flasks are connected, raise the tubes in the water-seal cylinders so that 
the generator has practically no pressure to overcome. Allow the carbon dioxid 
to run for a few minutes. Drop the tubes to the bottom of the cylinders, creating 
pressure in the flasks. Lift the rubber stoppers of the flasks alternately about a 
dozen times, in order to force out any air remaining in the flasks. Slightly raise the 
stopper on one of the flasks and quickly drop about 2 grams of sheet aluminium into 
the flask. The aluminium should be folded into a strip about 1 cm. wide and slightly 
bent so as to prevent it from striking directly on the bottom of the flask. After 
the aluminium has entirely dissolved, raise the tubes in the water-seal cylinders so 
as to allow carbon dioxid to pass through, place the flasks upon hot plates, and heat 
to boiling. After boiling for a few minutes, remove the flasks from the hot plates 
and cool in ice water (or cold running water), still maintaining within them an 



XII] METALS IN FOODS 175 

atmosphere of carbon dioxid. Lower the tubes in the cylinder. When cool, dis- 
connect the flasks one at a time, putting a glass plug into the carbon dioxid inflow. 
Wash the tubes, rubber stopper and sides of the flask with the air-free wash solution, 
add starch paste and titrate at once with the N/100 iodin. 

If it is desired to titrate by the excess method, run an excess of the N/100 iodin 
into the flask while it is still connected with the carbon dioxid stream. Then wash 
out the tubes and titrate the excess of iodin with the N/100 sodium thiosulphate. 

The rubber connections should be washed with water after each determination. 

8 COPPER.— TENTATIVE. 

Destroy organic matter as directed in 5. Concentrate the sulphuric acid residue 
by continued digestion to a volume of 10-15 cc, cool, dilute with a little water, trans- 
fer to a 400 cc. beaker, rinse the Kjeldahl flask with water, adding the rinsings to the 
contents of the beaker, dilute to about 200 cc. and boil to expel nitrous fumes. Cool, 
render the solution slightly alkaline with ammonium hydroxid and boil to expel the 
excess of ammonia. Add 5 cc. of concentrated hydrochloric acid for each 100 cc. 
of solution, heat to incipient boiling and saturate the solution with hydrogen sul- 
phid. Allow to stand on a steam bath for a few minutes until the sulphid flocculates, 
filter and wash the precipitate with hydrogen sulphid water. Protect the precipi- 
tate from contact with air as much as possible, use only hydrogen sulphid water for 
washing and carry out this operation without interruption. Reserve the filtrate 
for the determination of zinc, if necessary. Place the filter containing the copper 
sulphid precipitate in a small flask, add 4-5 cc. of concentrated sulphuric acid and 
the same amount of nitric acid and heat until white fumes appear. Continue the 
oxidation, adding a little nitric acid from time to time, until the liquid remains 
colorless upon heating to the appearance of white fumes. Cool, dilute with about 
30 cc. of water, add an excess of bromin water and boil until all bromin is expelled. 
Determine the copper as directed in VIII, 29, using N/100 sodium thiosulphate for 
the titration. 

9 ZINC— TENTATIVE. 

Proceed as directed in 8 to the point indicated by the sentence "Reserve the fil- 
trate for the determination of zinc, if necessary". Boil the filtrate, containing the 
zinc, to expel hydrogen sulphid and to reduce the volume to about 250-300 cc, add 
a drop of methyl orange and 5 grams of ammonium chlorid and make alkaline with 
ammonium hydroxid. Add dilute hydrochloric acid, drop by drop, until the re- 
action is faintly acid, then add 10-15 cc. of 50% sodium or ammonium acetate solu- 
tion and pass in hydrogen sulphid for a few minutes until precipitation is complete. 
Allow the precipitate to settle, filter, refilter, if necessary, until the filtrate is clear, 
and wash the precipitate twice with hydrogen sulphid water. Dissolve the precipi- 
tate on the filter with a little hydrochloric acid (1 to 3), wash the filter with water, 
boil the filtrate and washings to expel hydrogen sulphid, cool and add a distinct 
excess of bromin water. Then add 5 grams of ammonium chlorid and ammonium 
hydroxid until the color, caused by free bromin, disappears. Add hydrochloric 
acid (1 to 3), drop by drop, until the bromin color just reappears, then add 10-15 cc. 
of 50%.sodiimi or ammonium acetate solution and 0.5 cc. of 10% ferric chlorid solu- 
tion, or enough to precipitate all the phosphates. Boil until all the iron is precipi- 
tated. Filter while hot and wash the precipitate with water containing a little 
sodium acetate. Pass hydrogen sulphid into the combined filtrate and washings 



176 METHODS OF ANALYSIS 

until all the zinc sulphid, which should be pure white, is precipitated, filter upon a 
tared Gooch and wash with hydrogen sulphid water, containing a little ammonium 
nitrate. Dry the crucible and its contents in an oven, ignite at a bright red heat, 
cool and weigh as zinc oxid. Calculate the weight of metallic zinc. 

BIBLIOGRAPHY. 

1 U. S. Bur. Chem. Circ. 102; J. Soc. Chem. Ind., 1907, 26: 1115. 

2 J. Assoc. Official Agri. Chemists, 1915, 1: 257. 

3 Proc. Eighth Intern. Cong. Appl. Chem., 1912, 18: 35. 



Xm. FRUITS AND FRUIT PRODUCTS. 

1 PREPARATION OF SAMPLE.— TENTATIVE. 

All samples received in open packages (i.e., not in sterile condition) must be trans- 
ferred without delay to glass-stoppered containers and kept in a cool place. The 
determination of alcohol, total and volatile acids, solids and sugars, particularly 
in the case of fruit juices and fresh fruits, should be made at once as fermentation 
is liable to begin very soon. Portions for the determinations of sucrose and reducing 
sugar may be weighed and, after adding a slight excess of neutral lead acetate solu- 
tion, kept without fermenting for several days if desired. The various products 
are prepared as directed below. 

(a) Juices. — Prepare the fresh juice by pressing the well pulped fruit in a jelly 
bag and filtering through muslin. 

(b) Jellies and sirups. — Mix thoroughly to insure uniformity in sampling. Weigh 
60 grams into a 300 cc. flask, add water, dissolve by frequent shaking, then make up 
to the mark with water, and use aliquots for the various determinations. If the 
jelly contains starch or other insoluble material, mix thoroughly before taking the 
aliquots. 

(C) Fresh and dried fruits. — Pulp the whole, well cleaned fruit in a large mortar or 
by means of a food chopper and mix thoroughly. In the case of stone fruits, remove 
the pits and determine their proportion in a weighed sample. 

(d) Jams, marmalades, preserves and canned fruits. — Pulp thoroughly the entire 
contents of the jar or can, as directed under (C); with stone fruits remove the pita 
and, if desired, determine their proportion in a weighed sample. In the exami- 
nation of canned fruits it is often sufficient merely to examine the sirups in which the 
fruits are preserved. In such cases the liquor may be separated and treated as pre- 
scribed for juices. 

2 ALCOHOL.— TENTATIVE. 

Determine alcohol in 50 grams of the original material as directed under DC, 31 . 

3 TOTAL SOLIDS.— TENTATIVE. 

(a) Juices, jellies and sirups containing no insoluble matter. — Proceed as di- 
rected in IX, 3, 5, 7 or 10, employing the sample prepared as directed in 1 (a) or (D). 

(b) Fresh and dried fruits, jams, marmalades, preserves, canned foods and other 
products containing insoluble matter. — Weigh about 20 grams of pulped fresh fruit, 
or such an amount of fruit products as will give not more than 3-4 grams of dried 
material; if necessary to secure a thin layer of the material, add a few cc. of water, 
mix thoroughly, and dry as directed in DC, 3 or 4. 

It is to be noted that certain State and Federal regulations require the moisture 
in dried apples to be determined by drying for 4 hours at the temperature of boiling 
water. 

INSOLUBLE SOLIDS. 

4 Direct Method. — Tentative. 

Transfer 50 grams of the sample to a mortar by means of warm water and macerate 
thoroughly; then transfer to a muslin filter and wash thoroughly with about 500 cc. 
of warm water, stirring the pulp thoroughly on each addition of water. This amount 
of water is usually sufficient to remove all soluble material. In extreme cases increase 

177 



178 METHODS OF ANALYSIS [Chap. 

the washings to 1000 cc. Transfer the insoluble residue to an evaporating dish, dry 
and weigh. If it is desired to determine the alcohol precipitate, 18, cool the filtrate, 
make up to a definite volume and reserve for this determination. 

5 Indirect Method. — Tentative. 

Transfer 25 grams of the fruit product to a 250-500 cc. graduated flask, the size 
of the flask depending upon the volume of insoluble matter present, add water, 
shake thoroughly and make up to volume. Allow to settle and either filter or decant 
the supernatant liquid. Determine the soluble solids in an aliquot, as directed in 
3 (a). The fruit must be macerated thoroughly; the use of a mechanical shaker is 
advisable. The percentage of insoluble solids is the difference between the per- 
centage of the total solids and the percentage of soluble solids. 

6 TOTAL ASH.— OFFICIAL. 

Determine the ash as directed under VIII, 4, using 50 cc. of the solution of the 
jelly or diluted sirup, 1 (b), evaporated to dryness, or 25 grams of juice or of fresh 
or canned fruit, or 10 grams of jam, marmalade, preserves, or dried fruit. 

7 ALKALINITY OF THE ASH.— TENTATIVE. 

Into the platinum dish containing the ash introduce a measured excess of N/5 
nitric acid, heat to boiling, cool and add a few drops of methyl orange. Carefully 
rub up the ash with a rubber-tipped stirring rod and titrate the excess of acid with 
N/10 potassimn or sodium hydroxid. Express the result as the number of cc. of 
N/10 acid required to neutralize the ash from 100 grams of the sample. 

8 SULPHATE AND CHLORID.— TENTATIVE. 

Wash the solution of the ash, obtained in 7, into a 50 cc. flask and make up to the 
mark with water. Evaporate 25 cc. of this solution to dryness several times with con- 
centrated hj^drochloric acid, take up the final residue in a small amount of hot water, 
filter, wash the paper with hot water, acidify the filtrate with a few drops of hydro- 
chloric acid and determine the sulphate by precipitation with barium chlorid 
solution. From the weight of barium sulphate calculate the sulphate present as 
per cent of potassium sulphate. 

In the other portion of the solution determine the chlorin as directed under III, 15. 
The nitric acid added before making the titration will, if it contain enough nitrous 
oxid, completely destroy the red color of the methyl orange and leave a clear solu- 
tion for the titration. Calculate the chlorin as per cent of sodium chlorid. 

9 TOTAL ACIDITY.— TENTATIVE. 

Dilute 25 cc. of the solution of jelly or diluted sirup, 1 (b), or 10 grams of juice or 
fresh fruit, with recently boiled water to about 250 cc, or less if the sample be not 
highly colored; titrate the acid with N/10 alkali, using phenolphthalein as an in- 
dicator. In the case of highly colored products employ azolitmin solution or phenol- 
phthalein powder [XVI, 25] on a spot plate instead of phenolphthalein solution. 
Calculate the results as malic, citric or tartaric acid, specifying the acid used and 
expressing the results in grams per 100 cc. 

10 VOLATILE ACIDS.— TENTATIVE. 

Dissolve 10 grams of the sample, dilute to 25 cc. and distil in a current of steam, 
as directed under XVI, 27. Each cc. of N/10 alkali is equivalent to 0.0060 gram of 
acetic acid. 



XIII] FRUITS AND FRUIT PRODUCTS 179 

If FREE MINERAL ACIDS.— TENTATIVE. 

Proceed as directed under XIX, 26, 27 or 28. 
1 2 PROTEIN.— OFFICIAL. 

Proceed as directed under I, 18, 21 or 23, using 5 grams of jelly or other fruit 
product containing a large amount of sugar, or 10 grams of juice or fresh fruit and 
a larger quantity of the sulphuric acid if necessary for complete digestion. Multi- 
ply the percentage of nitrogen by 6.25 to obtain the percentage of protein. 

SUCROSE. 

13 By Polarization. — Official. 

Determine by polarizing before and after inversion, as directed under IX, 22 or 23. 

14 By Reducing Sugars Before and After Inversion. — Tentative. 
Proceed as directed under VIII, 18. 

15 REDUCING SUGARS.— TENTATIVE. 

Proceed as directed under VIII, 25, expressing the results as invert sugar. 

16 COMMERCIAL GLUCOSE.-TENTATIVE. 
Proceed as directed under IX, 25. 

1 7 DEXTRIN.— TENTATIVE. 

Dissolve 10 grams of the sample in a 100 cc. flask, add 20 mg. of potassium fluorid, 
and then about one fourth of a cake of compressed yeast. Allow the fermentation 
to proceed below 25°C. for 2-3 hours to prevent excessive foaming, and then incu- 
bate at 27°-30°C. for 5 days. At the end of that time, clarify with basic lead acetate 
solution and alumina cream, make up to 100 cc. and polarize in a 200 mm. tube. 
A pure fruit jelly will show a dextro or laevo-rotation of not more than a few tenths 
of a degree. If a polariscope having the Ventzke scale be used and a 10% solution 
polarized in a 200 mm. tube, the number of degrees read on the sugar scale of the in- 
strument multiplied by 0.8755 will give the percentage of dextrin, or the following 
formula may be used: 

Ti X r J . • C X 100 . , . , 

Percentage of dextrm = m wnicn 

198 X L X W 

C = degrees of circular rotation; 

L = length of tube in decimeters; 

W = weight of sample in 1 cc. 

18 ALCOHOL PRECIPITATE.— TENTATIVE. 

Evaporate 100 cc. of a 20% solution of jelly or diluted sirup, 1 (b), or of the wash- 
ings from the determination of insoluble solids, 4, to 20 cc. ; add slowly, with constant 
stirring, 200 cc. of 95% alcohol by volume and allow the mixture to stand overnight. 
Filter and wash with 80% alcohol by volume. Wash the precipitate from the 
filter paper with hot water into a platinum dish; evaporate to dryness; dry at 100°C. 
for several hours and weigh; then burn off the organic matter and weigh the residue 
as ash. Designate the loss in weight upon ignition as the alcohol precipitate. 

The ash should be chiefly lime and not more than 5% of the total weight of the 
alcohol precipitate. If it is greater than this, some of the salts of the organic acids 
have been brought down. Titrate the water-soluble portion of this ash with N/10 
acid, as any potassium bitartrate precipitated by the alcohol can thus be estimated. 



180 METHODS OF ANALYSIS [Chap. 

STARCH. 

19 Qualitative Test. — Tentative. 

First destroy the color of the jelly by treatment with sulphuric acid and potassium 
permanganate solution and then test with iodin solution. Bring the solution of 
jelly nearly to boiling, add several cc. of dilute sulphuric acid and then potassium 
permanganate solution until all color is destroyed. The starch remains unaffected 
by this treatment. The presence of starch is not necessarily an indication of its 
addition as an adulterant. It is usually present in small amount in the apple, and 
occasionally in other fruits, and unless it is found in the fruit product in consider- 
able amount its presence may be due to these natural sources. 

GELATINi. 

20 Qualitative Test. — Tentative. 

The presence of gelatin in jellies and jams is shown by the increased content of 
nitrogen. Precipitate a concentrated solution of jelly or jam with 10 volumes of 
absolute alcohol and determine nitrogen in the dried precipitate as directed under 

I, 18, 21 or 23. 

AGAR AGAR. 

QUALITATIVE TESTS. 

21 By Microscopic Examination'^. — Tentative. 

Heat the jelly with 5% sulphuric acid, add a crystal of potassium permanganate 
and allow to settle. If agar agar is present the sediment will be rich in diatoms 
which can be detected by the use of the microscope. 

22 By Precipitation^. — Tentative. 

Cover 30 grams of the jam or jelly with 270 cc. of hot water, stir until thoroughly 
disintegrated and boil for 3 minutes. Filter immediately, while still boiling hot, 
through a filter paper of texture similar to No. 597, S. & S. In the presence of agar 
agar a precipitate will form upon standing not longer than 24 hours. Filter, 
wash with cold water and dissolve from the paper by means of a very small amount 
of boiling water. Upon chilling this hot water solution a firm jelly will be formed 
that can be examined by the touch. This method will detect 0.2% of agar agar with 
certainty if the proportions of jam or jelly and water are strictly observed. 

TARTARIC ACID.— TENTATIVE. 

23 PREPARATION OF SOLUTION. 

Filter fruit juices and employ the filtrate directly. In the case of jellies filter 
the solution, prepared as directed in 1 (b), and employ the filtrate. In the case of 
sirups or substances containing insoluble matter like pulped fruit, jams, marmalades, 
etc., weigh 50-100 grams, the amount selected being dependent upon the content of 
solids, of the sample, prepared as directed in 1 (C) or (d), introduce into a 200 cc. 
graduated flask, make up to the mark with water, allow to stand for an hour, shake at 
frequent intervals, filter through a dry paper and use the filtrate. 

24 DETERMINATION. 

Determine the tartaric acid in 100 cc. of fruit juice or the same amount of a solu- 
tion of the sample, prepared as directed in 23, employing the method given under XVI, 
29, except that 20 cc. of alcohol are used in the precipitation instead of 15 cc. 



XIII] FRUITS AND FRUIT PRODUCTS 181 

MALIC ACID. 

25 Method I. — Tentative. 

(For fruit juices and similar products containing no tartaric acid and not 
ovet 15% of sugars and in which the color does not interfere 
with polarization.) 

Filter the sample, if necessary to secure a solution which can be readily polar- 
ized, and polarize with white light and a dichromate cell, using a 200 mm. tube if 
possible. 

If the sample contains free mineral acid, transfer a measured portion (75 cc. is a 
convenient volume) to a 100 cc. graduated flask, add enough standard alkali, cal- 
culated from the acidity as determined in 9, to neutralize the total acidity, dilute 
to the mark, mix well and filter. If no free mineral acids are present, it is unneces- 
sary to neutralize the sample. If neutralized, proper correction must be made for 
dilution in making the final calculation. 

Transfer 25 cc. of the sample, or a neutralized solution, to a flask graduated at 25 
and 27.5 cc, add about 2.5 grams of powdered uranyl acetate, and shake vigorously 
at frequent intervals for 3 hours, keeping the mixture well protected from light. 
If all of the uranyl acetate dissolves, add more so that a small amount remains 
undissolved at the end of 3 hours. Dilute the solution to the 27.5 cc. mark with 
saturated uranyl acetate solution, mix well and filter, if necessary, through a folded 
filter. Polarize, if possible, in a 200 mm. tube. If the solution is too dark to polarize 
in a 200 mm. tube, a 100 or 50 mm. tube may be used. Multiply the reading by 1.1 
to correct for the dilution. 

Multiply the algebraic difference in degrees Ventzke between the 2 readings cal- 
culated to the basis of a 200 mm. tube by the factor 0.036 to obtain the weight of 
malic acid in the sample in grams per 100 cc. 

Make all polarizations at the same room temperature with white light and with 
a dichromate cell. Make at least 6 readings in each case and take an average of 
these. 

In the case of dark colored fruit juices which cannot be polarized readily, approxi- 
mately quantitative results may be obtained by adding to the solutions a few drops 
of bromin, shaking thoroughly and filtering just before polarization. 

Method II. — Tentative. 

(Approximate determination for fruit juices and similar products con- 
taining no tartaric acid and more than 15% of sugars.) 

26 PREPARATION OF SOLUTION^. 

Weigh out 25 grams of the sample and transfer to a 600 cc. beaker with a little 
95% alcohol by volume. Add alcohol a little at a time until 200 cc. have been added, 
stirring the mixture well, and warming, if necessary, to insure solution of all alcohol- 
soluble substances. Filter on a Bilchner funnel, using suction, and thoroughly 
wash the precipitated pectins and insoluble matter with 95% alcohol, disregarding 
any slight turbidity which may appear in the filtrate after the washings have 
been added. From 9, calculate the amount of N/4 barium hydroxid required 
nearly to neutralize the acidity in the 25 grams of sample taken. To the com- 
bined filtrate and washings in an Erlenmeyer flask add the calculated quantity of 
barium hydroxid solution, stir until reaction is complete and then add 3-5 drops, or 
more if required, of 50% barium acetate solution to msure an excess of barium. 
Make up the voliune of the mixture to about 375 cc. (not less) with alcohol, and re- 
flux until the precipitate settles readily after being shaken. This may require 3-4 



182 METHODS OF ANALYSIS [Chap. 

hours. Filter with suction and thoroughly wash the precipitate in the flask and 
on the paper with 95% alcohol by volume. Transfer the portion on the filter to 
the original flask, rinsing the paper with a jet of hot water. Digest the pre- 
cipitate with hot water, containing 2 grams of sodium sulphate in solution, un- 
til the reaction is complete, and boil until the barium sulphate precipitate settles 
readily. Concentrate by evaporation, if necessary, and transfer to a 100 cc. vol- 
umetric flask with a little hot water, cool, make up to volume with water and 
filter. 



27 



DETERMINATION. 



Transfer 25 cc. of the filtrate, obtained in 26, to a flask graduated at 25 and 
27.5 cc, add about 2.5 grams of pulverized uranyl acetate and shake vigorously at 
frequent intervals for 3 hours, keeping the solution well protected from light. If all 
the uranyl acetate dissolves, add more so that a small amount remains undissolved 
at the end of 3 hours. Dilute the solution to the 27.5 cc. mark with saturated uranyl 
acetate solution, mix well, filter if necessary, and polarize in a 200 mm. tube, using 
the same precautions as described in 25. Multiply the reading, calculated to the 
basis of a 200 mm. tube, by 1.1 to correct for the dilution. 

Polarize another portion of the filtrate, obtained in 26, which has not been treated 
with uranyl acetate. Multiply the algebraic difference in degrees Ventzke between 
the 2 readings, calculated to the basis of a 200 mm. tube, by the factor 0.036 to obtain 
the weight of malic acid in grams per 100 cc. in the solution as obtained in 26. 

Method III. — Tentative. 
(Approximate determination for products containing tartaric acid.) 

28 PREPARATION OF SOLUTION^ 

Prepare the sample as directed under 26 up to the point of filtration and washing 
of the barium malate precipitate, then dry the precipitate thoroughly and transfer 
the portion on the filter to the original flask, rinsing the paper with a jet of hot 
water. Digest the precipitate with hot water, transfer to a 100 cc. volumetric 
flask with a little hot water, cool, make up to volume with water and filter to re- 
move insoluble barium tartrate. This amount of water is sufficient to dissolve 
barium malate up to amounts as large as approximately 0.9 gram in 100 cc. More 
than 100 cc. of water must be used when more than 0.9 gram of barium malate 
is present. The amount of barium tartrate dissolved by hot water is so small as to 
affect only slightly the polarization after treatment with uranyl acetate. 

29 DETERMINATION. 

Proceed as directed in 27, using the solution prepared as directed in 28. 

CITRIC ACID''.— TENTATIVE. 
^Applicable in the presence of sugar and malic and tartaric acids.) 

30 REAGENTS. 

(a) Barium hydrozid solution. — Approximately N/4. 

(b) 50% barium acetate solution. 

(C) Sulphuric acid (1 to 1) and (1 to 5). 

(d) Potassium or sodium bromid solution. — Dissolve 15 grams of potassium bromid 
in 40 cc. of water or 16 grams of sodium bromid in 50 cc. of water. 



XIII] FRUITS AND FRUIT PRODUCTS 183 

(e) 5% potassium permanganate solution. 

(f) Ferrous sulphate solution. — Dissolve 20 grams of ferrous sulphate in 100 cc. 
of water containing 1 cc. of concentrated sulphuric acid. 

(^) Bromin water. — Freshly prepared, saturated solution. 

31 DETERMINATION. 

Proceed as directed in 26 up to "Filter with suction and thoroughly wash the 
precipitate in the flask and on the paper with 95% alcohol by volume". Transfer the 
precipitate from the filter to the flask with a jet of hot water, boil until alcohol 
can no longer be detected by odor, and add enough of the sulphuric acid (1 
to 5) to precipitate all the barium originally added and to allow 2 cc. in excess. 
Evaporate by careful boiling to a volume of 60-70 cc, cool and add 5 cc. of freshly 
prepared saturated bromin water, or enough to show a distinct excess. Transfer 
with water to a 100 cc. volumetric flask and dilute to the mark at standard 
temperature. Mix thoroughly, allow the precipitate to settle and filter through 
a dry paper. The precipitate may be separated by centrifugalizing and the super- 
natant liquid decanted, if necessary. Pipette an aliquot of the filtrate, containing 
not more than 250 mg. of citric acid, calculated from the total acidity of the sample, 
into a 300 cc. Erlenmeyer flask. If possible, the amount of citric acid in the ali- 
quot should exceed 50 mg. Add 10 cc. of the sulphuric acid (1 to 1) and 5 cc. of the 
potassium or sodium bromid solution, mix, warm the flask in a water bath to48°-50*'C. 
and allow it to remain in the bath for 5 minutes. After removing from the bath add 
rapidly from a pipette, drop by drop with frequent interruptions, 25 cc. of the 5% 
potassium permanganate solution and shake vigorously; avoiding a temperature 
during oxidation exceeding 55°C. Set the flask aside until the hydrated peroxid of 
manganese begins to settle. The supernatant liquid should be dark brown, showing 
an excess of permanganate; if an excess is not indicated, add more permanganate. 
Shake, again set aside to settle and repeat this operation until the precipitate 
assumes a yellow color and most of it has dissolved. Finally, while the solution 
is still warm, remove the last undissolved portion of hydrated peroxid of manganese 
precipitate and also the excess of bromin by adding, drop by drop, the clear ferrous 
sulphate solution. Allow the solution to cool, shaking occasionally. If the opera- 
tions have been properly conducted, a heavy white precipitate of pentabromacetone 
is obtained which becomes crystalline on occasional shaking and in this condition 
is entirely insoluble in water. Allow the mixture to stand overnight, collect it by 
means of gentle suction on a tared Gooch crucible provided with a thin pad of asbestos, 
previously dried over sulphuric acid in a vacuum desiccator, wash with water slightly 
acidified with sulphuric acid and finally wash twice with water. Dry the precipitate 
to constant weight over sulphuric acid in a vacuum desiccator, protecting the precipi- 
tate from strong light. The weight of pentabromacetone multiplied by the factor 0.424 
gives the equivalent weight of anhydrous citric acid (HsCeHjO?). Occasionally the 
pentabromacetone is first obtained in the form of oily droplets. These become 
crystalline on standing or on cooling and are usually discolored by negligible traces 
of manganese or iron. 

The above method may be applied directly to the sample without previous pre- 
cipitation of the citric acid as the barium salt when the amount of sugar or other 
permanganate reducing substances is not excessive. In this case begin the deter- 
mination with the addition of 2 cc. of sulphuric acid (1 to 5) and the treatment 
with bromin water. 

32 METALS.— TENTATIVE. 

Proceed as directed under XII. 



184 METHODS OF ANALYSIS 

33 PRESERVATIVES— TENTATIVE. 
Proceed as directed under X. 

34 COLORING MATTERS— TENTATIVE. 
Proceed as directed under XI. 

35 SWEETENING SUBSTITUTES.— TENTATIVE. 
Proceed as directed under X, 1 2, 36 or 37. 

BIBLIOGRAPHY. 

1 Chem. Ztg., 1895, 19: 552. 

2 Z. angew. Mikros., 1896, 2: 260. 

3 Z. Nahr. Genussm., 19U, 21: 185. 

* J. Assoc. Official Agri. Chemists, 1915, 1: 480. 

s Ibid.; U. S. Bur. Chem. Bull. 162, p. 65. 

« Arch. Chem. Mikros., 1914, 7: 285; Abs. Z. Nahr. Genussm., 1915, 30: 309. 



XIV. CANNED VEGETABLES. 

1 PHYSICAL EXAMINATION^.— TENTATIVE. 

Note carefully the external appearance of the packages to detect the presence of 
"leakers", "swells" or "springers". In general the ends of sound tins of canned 
vegetables are slightly concave. On opening the package note the relative pro- 
portion of solid and liquid contents and the level of the solids and of the total con- 
tents in the tin. Note the general appearance, odor, flavor, color and size of the 
vegetables; appearance of the liquor or brine, whether clear or turbid, and the con- 
dition of the inner walls of the container, especially as to blackening and corrosion. 
In all instances the analyst should familiarize himself with the normal appearance, 
odor, color, flavor and other properties of the product under examination. Care- 
ful macroscopic or microscopic examination should be made for worm infestation, 
mold, dirt, or other evidence of decomposition or filth. 

2 PREPARATION OF SAMPLE.— TENTATIVE. 

The preparation of the sample for analysis depends upon the character of the 
product and the determinations to be made. Samples in which only the solid or 
liquid portion is required should be treated as follows: Weigh the full can, open, 
pour off the liquid, allow the solid portion to drain for a minute, re-weigh the can 
and drained vegetables, then remove the solid portion and weigh the dry, empty 
can. The method selected for draining the vegetables is dependent upon the nature 
and condition of the sample. In most cases it is sufficient to cut around the cover 
and before turning it back allow the liquor to drain through the slit. Whenever a 
portion of the solid material would escape with the liquor by this procedure, drain 
upon a piece of cheese-cloth. From the weights thus obtained determine the per- 
centage of liquid and solid contents. If only the solid portion is required, separate 
in a similar manner and grind thoroughly the drained vegetables in a mortar or 
food chopper. If a composite of the solid and liquid portion is required, grind 
thoroughly the contents of the can in a mortar or food chopper. In all cases mix 
thoroughly the portion used and preserve the balance in glass-stoppered containers. 
Unless the analysis is to be completed in a reasonably short time, determine the 
moisture in a portion of the sample prepared as above and, in order to prevent decom- 
position, dry the remainder and then expose to air until it becomes air-dry, grind, mix 
thoroughly and preserve in glass-stoppered containers. A second moisture determi- 
nation is required in this procedure. 

3 MOISTURE.— TENTATIVE. 

Dry a quantity of the sample, representing about 2 grams of dry material, as 
directed in IX, 2. 

4 ASH.— OFFICIAL. 

Determine total ash as directed in VIII, 4. 

5 SALT.— OFFICIAL. 

^Determine chlorin as directed under III, 15, and express the result in terms of 
sodium chlorid. 

185 



186 METHODS OF ANALYSIS 

6 SUGARS.— TENTATIVE. 

Determine reducing sugars and sucrose as directed in VIII, 58 and 59, varying 
the weight of the sample employed according to its sugar content. 

7 TOTAL ACIDS.— TENTATIVE. 

Proceed as directed in XVI, 25. Express the result as citric acid; 1 cc. of N/10 
alkali is equivalent to 0.0070 gram of crystallized citric acid. 

8 VOLATILE ACIDS.— TENTATIVE. 

Proceed as directed in XVI, 27. Express the results as acetic acid; 1 cc. of N/10 
alkali is equivalent to 0.0060 gram of acetic acid. 

9 PRESERVATIVES.— TENTATIVE. 
Proceed as directed under X. 

10 COLORING MATTERS.— TENTATIVE. 

Proceed as directed under XI. 

1 1 METALS.— TENTATIVE. 

Proceed as directed under XII. 

BIBLIOGRAPHY. 

/U.S. Bur. Chem. Bulls. 125 and 151 ; U. S. Dept. Agr. Bull. 196; U. S. Bur. Chem. 
Circ. 54; Research Laboratory, National Canners Association, Bull. 2. 



XV. CEREAL FOODS. 
WHEAT FLOUR. 

1 MOISTURE.— OFFICIAL. 
Determine moisture as directed in VIII, 2. 

2 ASH— OFFICIAL. 

Determine ash as directed in VIII, 4, using 5 grams of the flour. 

3 CRUDE FAT OR ETHER EXTRACT.— OFFICIAL. 

Determine the ether extract as directed in VIII, 1 0. With fine flour the addition 
of an equal weight of clean, dry sand is frequently necessary. 

4 CRUDE FIBER.— OFFICIAL. 
Determine crude fiber as directed in VIII, 68. 

5 ACIDITY OF WATER EXTRACT.— TENTATIVE. 

Weigh 18 grams of the flour into a 500 cc. Erlenmeyer flask and add 200 cc. of 
carbon dioxid-free water. Place the flask, loosely stoppered, for an hour in a water 
bath kept at 40°C., shaking occasionally. Filter upon a dry, folded filter, return- 
ing the first 10-15 cc. of the filtrate to the filter. Titrate 100 cc. of the clear filtrate 
with N/20 sodium hydroxid, using phenolphthalein as an indicator. Each cc. of 
N/20 sodium hydroxid is equivalent to 0.05% acidity as lactic acid. 

6 SUGARS.— TENTATIVE. 

Determine reducing sugars and sucrose as directed in VIII, 58 and 59. 

7 PROTEIN.— OFFICIAL. 

Determine nitrogen as directed in I, 18, 21 or 23. Multiply the percentage of 
nitrogen by 5.7 to obtain the percentage of protein. 

ALCOHOL-SOLUBLE PROTEIN. 

8 Method I. {By nitrogen determination) — Tentative. 

Transfer 4 grams of the flour to a 150-200 cc. bottle or Erlenmeyer flask and add 
100 cc. of 70% alcohol by volume, taking care that none of the material sticks 
to the bottom of the container. Shake thoroughly 10-12 times at intervals of 30 
minutes at room temperature, or shake continuously in a shaking machine for 
an hour, and then set aside overnight. Shake thoroughly once more, allow to settle 
and filter through a dry, folded filter, returning the first runnings to the filter until 
a clear filtrate is obtained. Pipette 50 cc. of the filtrate, equivalent to 2 grams of 
the sample, into a Kjeldahl flask, dilute with 100 cc. of water to prevent frothing 
during digestion and determine nitrogen as directed in I, 18, 21 or 23. 

187 



188 METHODS OF ANALYSIS [Chap. 

9 Method II. {By Polarization) — Tentative. 



Millon's reagent. — Dissolve metallic mercury in an equal weight of concentrated 
nitric acid and dilute the solution with an equal volume of water. The freshly 
prepared solution must be used. 

1 DETERMINATION. 

Weigh 15.97 grams of the flour into a 300 cc. flask and add 100 cc. of alcohol (sp. 
gr. 0.90). Shake at 30 minute intervals for 3 hours and then let stand overnight. 
Filter through a dry, folded filter and polarize in a 200 mm. tube. Precipitate the 
proteins in 50 cc. of the filtrate by the addition of 5 cc. of Millon's reagent. Shake, 
filter and polarize the filtrate in a 200 mm. tube. Multiply the reading in degrees 
Ventzke by 1.1 to correct for the dilution and deduct the product from the first 
reading. This difference multiplied by 0.2 gives the per cent of gliadin^ nitrogen. 

1 1 PROTEIN SOLUBLE IN 5 PER CENT POTASSIUM SULPHATE SOLUTION.— TENTATIVE. 

Weigh 6 grams of the flour into a 200 cc. flask and introduce exactly 100 cc. of 
5% potassium sulphate solution. Shake at 30 minute intervals for 3 hours and 
let stand overnight or, better still, agitate at moderate speed in a shaker for 3 hours, 
let settle 30 minutes, filter and determine the nitrogen in 50 cc. of the filtrate as 
directed in I, 18, 21 or 23. 

12 GLOBULIN AND ALBUMIN (EDESTIN AND LEUCOSIN) AND AMINO NITROGEN^.— 

TENTATIVE. 

Weigh 10 grams of the flour into a 500 cc. Erlenmeyer flask, add 250 cc. of 1% 
sodium chlorid solution, stopper the flask and shake thoroughly. Let stand, with 
occasional shaking, for 3 hours, filter through dry paper and evaporate 100 cc. of 
the filtrate to a small volume in a Kjeldahl digestion flask with 5 cc. of concentrated 
sulphuric acid. Add the remainder of the sulphuric acid and determine the nitro- 
gen as directed in I, 18, 21 or 23. To a second 100 cc. of the filtrate add 5 cc. of 20% 
phosphotungstic acid solution, shake thoroughly, allow to settle and filter by de- 
cantation. Wash slightly with water, concentrate the filtrate with 5 cc. of sul- 
phuric acid in a Kjeldahl flask and determine the nitrogen (amino) as directed in 
I, 18, 21 or 23. Deduct the amino nitrogen from the nitrogen found in the first frac- 
tion to obtain the nitrogen as globulin and albumin'. 

1 3 GLUTENIN.— TENTATIVE. , 

Deduct the sum of the potassium sulphate-soluble nitrogen, 1 1 , and the alcohol- 
soluble nitrogen, 8, from the total nitrogen, 7, and multiply the difference by 5.7. 

14 COLD WATER-SOLUBLE EXTRACT.— TENTATIVE. 

Weigh 20 grams of the flour into a 500 cc. Erlenmeyer flask and add gradually 
200 cc. of water at 10°C., shake vigorously when about 50 cc. of water have been 
added and continue shaking during the addition of the remainder. Allow to stand 
at 10°C. for 40 minutes, shaking occasionally. Filter through a large, dry, coarse 
filter paper, returning the first runnings to the filter until a clear filtrate is obtained. 
Pipette 20 cc. of the clear filtrate into a tared dish, evaporate to dryness on a steam 
bath, and dry to constant weight in an oven at 100°C. for periods of 30 minutes. 



XV] CEREAL FOODS 189 

GLUTEN. 

15 Bamihl Test. {Qualitative) — Tentative. 

Place a very small quantity (about 1.5 mg.) of the flour on a microscope slide, 
add a drop of water, containing 0.2 gram of water-soluble eosin in 1 liter, and mix 
by means of a cover-glass, holding the latter at first in such a manner that it is raised 
slightly above the slide, and taking care that none of the flour escapes from beneath 
it. Finally allow the cover-glass to rest on the slide and rub it back and forth 
until the gluten has collected into rolls. The operation should be carried out on 
a white paper so that the formation of gluten rolls can be noted. Wheat flour, or 
other flours containing gluten, show by this treatment a copious amount of gluten, 
which absorbs the eosin with avidity, assuming a carmine color. Rye and corn 
flour yield only a trace of gluten, and buckwheat flour no appreciable amount. 
The preparations are best examined with the naked eye, thus gaining an idea of 
the amount of gluten present. If the flour is coarse, or contains a considerable amount 
of bran elements, as is true of buckwheat flour and low-grade wheat flour, the test 
should be made after bolting, as the bran particles and coarse lumps interfere with 
the formation of gluten rolls. 

16 Quantitative Method. — Tentative. 

Weigh 25 grams of the flour into a cup or porcelain mortar, add sufficient tap water 
(about 15 cc.) to form a firm dough ball and work into a dough with a spatula or 
pestle, taking care that none of the material adheres to the utensil employed. Allow 
the dough to stand in water at room temperature for an hour, then knead gently 
in a stream of tap water until the starch and all soluble matters are removed. This 
operation requires approximately 12 minutes and should be performed over bolting 
cloth or a horsehair sieve. To determine if the gluten is starch-free let 1 or 2 drops 
of the wash water, obtained by squeezing the gluten, fall into a beaker containing 
perfectly clear water. If starch is present a cloudiness appears. Allow the gluten 
thus obtained to stand in water for an hour, then press as dry as possible between 
the hands, roll into a ball, place in a tared, flat-bottomed dish and weigh as moist 
gluten. Transfer to an oven, dry to constant weight at 100°C. (about 24 hours), 
cool and weigh as dry gluten. 

CHLORIN. 

17 Qualitative Test. {Chlor in-Bleached Flours) — Tentative. 

Extract 30 grams of the flour with gasoline and allow the latter to evaporate. 
A small amount of oil remains. Heat a piece of copper wire in a colorless gas flame 
until it is black and no longer colors the flame green. Dip the hot end of the wire 
into the oil and again bring into the flame. If chlorin or bromin has been used as 
a bleaching agent, a green or blue coloration is produced. 

1 8 Quantitative Method. {Added Chlorin in Chlorin-Bleached Flours) — Tentative. 

Weigh 20 grams of the flour into a flat-bottomed aluminium dish, 8-10 cm. in 
diameter, and dry 5 hours in a boiling water or steam oven, transfer, with as little 
exposure to the air as possible, to a continuous fat extractor, and extract for 16 hours 
with anhydrous alcohol-free ether, which is also free from chlorin. Transfer the 
ether extract to a nickel dish and add 25 cc. of a solution containing 25 grams of 
sodium hydroxid and 15 grams of sodium nitrate per liter. Place the dish on a 
steam bath, evaporate to dryness and ignite in a muffle at a dull red heat until 



190 METHODS OF ANALYSIS [Chap. 

the contents are thoroughly charred. Extract the charred mass with 25 cc. of 1% 
nitric acid and filter. Return the residue to the dish, char and again extract with 
25 cc. of 1% nitric acid, filter, wash with hot water, return to the dish and ignite 
,to a white ash. Dissolve the ash in 5% nitric acid and add the solution to the filtrates 
previously obtained. Determine the chlorin in the combined filtrates either gravi- 
metrically, as directed in I, 16 (a), or volumetrically, as directed in III, 15, using 
N/50 solutions for greater accuracy. 

NITRITE NITROGEN.— TENTATIVE. 

19 REAGENTS. 

(a) Sulphanilic acid solution. — Dissolve 0.5 gram of sulphanilic acid in 150 cc. of 
20% acetic acid. 

(b) Alpha-naphthylamin hydrochlorid solution. — Dissolve, by heating, 0.2 gram 
of the salt in 150 cc. of 20% acetic acid. 

(C) Standard nitrite solution. — Dissolve 0.1097 gram of dry C. P. silver nitrite 
in about 20 cc. of hot water, add 0.10 gram of C. P. sodium chlorid, shake until 
the silver chlorid flocculates and make up to 1 liter. Draw off 10 cc. of the 
clear solution and dilute to 1 liter. Each cc. of the last solution is equivalent to 
0.0001 mg. of nitrogen as nitrite. [Cf. IV, 12 (d)] 

The silver nitrite may be prepared as follows : To a cold solution of about 2 
grams of sodium or potassium nitrite in 50 cc. of water, add a solution of silver 
nitrate as long as a precipitate appears. Decant the liquid and thoroughly wash 
the precipitate with cold water. Dissolve in boiling water. On cooling the silver 
nitrite crystallizes out. Dry the crystals in the dark at ordinary temperature (pre- 
ferably in a vacuum). 

20 DETERMINATION. 

(1) Select a series of 100 cc. volumetric flasks of uniform dimensions and color. 
Place 2 grams of high-grade, nitrite-free flour in each; add approximately 70 cc. of 
nitrite-free water and shake until the flour is thoroughly moistened. Add to these 
flasks varying amounts of the standard sodium nitrite solution, so that a series of 
comparison standards will be obtained having a range covering the probable nitrite 
content of the unknown sample. Reserve 1 flask for a blank test. In order to 
avoid making a large series of standards it is well to make a preliminary test to as- 
certain the approximate nitrite content of the unknown. Where the quantity of 
nitrite present is small, the nitrite solution in the flasks may be increased by 0.4 
cc. each. Where bleaching is excessive, 1 gram of flour may be used throughout, 
or the standards may be given a wider variation in nitrite content. 

To each of 2 similar flasks add 2 grams of the flour and 90 cc. of water; shake 
thoroughly and digest all the flasks, including the blank, in a water bath at 40°C. 
for at least 15 minutes; add 2 cc. each of the sulphanilic acid and alpha- 
naphthylamin hydrochlorid solutions to each flask. Continue the digestion at 
40°C. for an additional 20 minutes. The color must be developed in all the flasks 
under conditions as nearly uniform as possible. Make up to the marks with nitrite- 
free water and compare the unknown with the series of standards. This may be 
done in a large, white, enameled pan; the effect of the turbidity, due to the flour, 
being minimized by the white background. The solutions should be allowed to 
subside and should not be shaken during comparison; or, 

(2) Weigh 20 grams of the flour into a 500 cc. Erlenmeyer flask, add 200 cc. of 
nitrite-free water, previously warmed to 40°C., and close the flask with a rubber 
stopper. Shake vigorously for 5 minutes and digest for an hour in a water bath. 



XV] CEREAL FOODS 191 

keeping the temperature of the liquid in the flask at 40°C. and shaking at 10 minute 
intervals. Finally filter on a dry, nitrite-free, folded filter. Return the first run- 
nings to the filter until a clear filtrate is obtained. Pipette 50 cc. of the filtrate and 
50 cc. of the standard nitrite solution into small flasks; add to each, 50 cc. of water, 
2 cc. each of the sulphanilic acid and alpha-naphthylamin hydrochlorid solutions, 
shake and allow to stand an hour to bring out the color. Compare the 2 solutions 
in a colorimeter. Divide the height of the column of the standard solution by that 
of the solution of the sample to obtain the parts of nitrogen as nitrous acid (free 
and combined) per million of flour. 

21 GASOLINE COLOR VALUE.— TENTATIVE. 

Place 20 grams of the flour in a wide-mouthed, glass-stoppered 120 cc. bottle and 
add 100 cc. of colorless gasoline. Stopper tightly and shake vigorously for 5 minutes. 
After standing 16 hours, shake again for a few seconds until the flour has been loos- 
ened from the bottom of the bottle and thoroughly mixed with the gasoline, then 
filter immediately on a dry 11 cm. paper into an Erlenmeyer flask, keeping the fun- 
nel covered with a watch glass to prevent evaporation. In order to secure a clear 
filtrate, a certain quantity of the flour should be allowed to pass over onto the paper 
and the first portion of the filtrate passed through a second time. It will be found 
convenient to fit the filter paper to the funnel by means of water and dry thoroughly 
either by standing overnight in a well-ventilated place or by heating. 

Determine the color value of the clear gasoline solution in a Schreiner or similar 
colorimeter, using for comparison a 0.005% potassium chromate solution. This solu- 
tion corresponds to a gasoline number of 1.0 and is conveniently prepared by dilu- 
ting 10 cc. of a 0.5% solution to 1 liter. The colorimeter tube, containing the 
gasoline solution, should first be adjusted so as to read 50 mm., then the tube 
containing the standard chromate solution raised or lowered until the shades of yellow 
in both tubes match. The reading of the chromate solution, divided by the reading 
of the gasoline solution, gives the gasoline color value. The color value may be deter- 
mined also in Nessler tubes, using for comparison potassium chromate solutions 
of various dilutions prepared from a 0.5% solution and filling the tubes in all cases 
to the height of 50 mm. 

BIBLIOGRAPHY. 

' U. S. Bur. Chem. Bull. 152, p. 104, 
2 Ibid., 81, p. 124. 
2 Ibid., 122, p. 54. 



XVI. WINES. 

1 PHYSICAL EXAMINATION,— TENTATIVE. 

Note the followinj?: whether the container Ls "?;ottle full"; the apjjearanoe of 
the wine, whether there is any sediment and if it is bright or turbid; condition when 
opened, whether still, gaseous or carbonated; color and depth of color; odor, whether 
vinous, acetous, pleasant or foreign; and taste, whether vinous, acetous, sweet, 
dry or foreign. 

2 PREPARATION OF SAMPLE.— TENTATIVE. 

If gas is contained in the wine, remove it by pouring back and forth in heakerg. 
Filter the wine, regardless of appearance, before analysis and determine immedi- 
ately the specific gravity and such ingredients as alcohol, acids and sugars as are 
liable to change through exposure. 

3 SPECIFIC GRAVITY. -TENTATIVE. 

Determine the specific gravity at -45—^' hy means of a pycnometer. 

4 AiCOHOL,— TENTATIVE. 

fa) By volume.— Measnr a 100 cc. of the liquid at 20'*C. into a ?/]lO-r0) cc. distilla- 
tion flask, add .50 cc. of water, attach the flask to a vertical condenser by means of 
a l)ent tube and distil almost 100 cc, making up to 100 cc. volifme when cooled 
to 20°C. Foaming, which sometimes occurs, esf>e,cially with young wines, may be 
prevented by the addition of a small amount of tannin. To determine the alcohol in 
wines which have undergone acetous fermentation and contain an abnormal amount 
of acetic acid, exactly neutralize the portion taken with sodium hydroxid solution 

before distilling. This is unnecessary, however, in wines of normal taste and odor. 

20* (' 
Determine the specific gravity of the distillate at ^» " ■ and obtain the correspond- 
ing p<:;rcentage of alcohol by volume from 5. 

(h) (iram.% per 100 r.r,. — From the sj)f;cific gravity of the distillate, obtained in 
(a), ascertain from 5 the corresponding alcohol content in grams per 100 cc. 

CC; Hy vmghl. — Divide the number of grams in the IfX) cc. of distillate, as ol> 
tained in (b), by the weight of the sample as calculated from its specific gravity. 

(d) By immersif/n refractometer. — The percentages of alcohol, as det.ermined in 
(a) and (C), may be verified by determining the immersion refractometer reading 
of the distillate and obtaining, from 8, the corresponding percentages of alcohol. 



19.3 



194 



METHODS OF ANALYSIS 



[Chap. 



Table 16.— Alcohol Table. 

(Calculated by the U. S. Bureau of Standards from its experimental results^) 

For calculating the percentages of alcohol in mixtures of ethyl alcohol and water from their 

specific gravities. 



BPECIFIC 


ALCOHOL 


SPECIFIC 


ALCOHOL 


SPECIFIC 


ALCOHOL 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


QRAVITT 

20° 0. 


Per cent 


Per 


Grams 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 




at 20° C. 


weight 


100 CO. 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.99823 


0.00 


0.00 


0.00 


0.99492 


2.25 


1.79 


1.78 


0.99174 


4.50 


3.58 


3.55 


0.99815 


05 


04 


0.04 


0.99485 


2.30 


1.82 


1.81 


0.99168 


4.55 


3.62 


3.59 


0.99808 


0.10 


0.08 


0.08 


0.99477 


2 35 


1.86 


1.85 


0.99161 


4.60 


3.66 


3.63 


0.99800 


0.15 


0.12 


0.12 


0.99470 


2.40 


1.90 


1.89 


0.99154 


4.65 


3.70 


3.67 


0.99793 


0.20 


0.16 


0.16 


0.99463 


2.45 


1.94 


1.93 


0.99147 


4.70 


3.74 


3.71 


0.99785 


25 


0.20 


0.20 


0.99456 


2 50 


1.98 


1.97 


0.99140 


4.75 


3.78 


3.75 


0.99778 


30 


0.24- 


0.24 


0.99449 


2.55 


2.02 


2.01 


0.99133 


4.80 


3.82 


3.79 


0.99770 


35 


0.28 


0.28 


0.99442 


2 60 


2.06 


2.05 


0.99127 


4.85 


3.86 


3.83 


0.99763 


40 


0.32 


0.32 


0.99434 


2.65 


2.10 


2.09 


0.99120 


4.90 


3.90 


3.87 


0.99755 


0.45 


0.36 


0.36 


0.99427 


2.70 


2.14 


2.13 


0.99113 


4.95 


3.94 


3.91 


0.99748 


50 


0.40 


0.40 


0.99420 


2.75 


2.18 


2.17 


0.99106 


5 00 


3.98 


3.95 


0.99741 


55 


0.44 


0.44 


0.99413 


2.80 


2.22 


2.21 


0.99100 


5 05 


4.02 


3.99 


0.99734 


0.60 


0.47 


0.47 


0.99405 


2 85 


2.26 


2.25 


0.99093 


5.10 


4.06 


4.03 


0.99726 


65 


0.51 


0.51 


0.99398 


2 90 


2.30 


2.29 


0.99087 


5.15 


4.10 


4.07 


0.99719 


0.70 


0.55 


0.55 


0.99391 


2.95 


2.34 


2.33 


0.99080 


5.20 


4-14 


4.10 


0.99711 


0.75 


0.59 


0.59 


0.99384 


3.00 


2.38 


2.37 


0.99073 


5 25 


4.18 


4.14 


0.99704 


0.80 


0.63 


0.63 


0.99377 


3 05 


2.42 


2.41 


0.99066 


5 30 


4.22 


4.18 


0.99697 


0.85 


0.67 


0.67 


0.99370 


3.10 


2.46 


2.45 


0.99060 


5 35 


4.26 


4.22 


0.99690 


0.90 


0.71 


0.71 


0.99362 


3 15 


2.50 


2.49 


0.99053 


5 40 


4.30 


4.26 


0.99682 


0.95 


0.75 


0.75 


0.99355 


3 20 


2.54 


2.53 


0.99047 


5.45 


4.34 


4.30 


0.99675 


1.00 


0.79 


0.79 


0.99348 


3 25 


2.58 


2.57 


0.99040 


5.50 


4.38 


4.34 


0.99667 


1 05 


0.83 


0.83 


0.99341 


3 30 


2.62 


2.60 


0.99033 


5.55 


4-42 


4.38 


0.99660 


1 10 


0.87 


0.87 


0.99334 


3 35 


2.66 


2.64 


0.99026 


5 60 


4.46 


4.42 


0.99652 


1.15 


0.91 


0.91 


0.99327 


3 40 


2.70 


2.68 


0.99020 


5.65 


4.50 


4.46 


0.99645 


1.20 


0.95 


0.95 


0.99320 


3.45 


2.74 


2.72 


0.99013 


6.70 


4.54 


4.50 


0.99638 


1 25 


0.99 


0.99 


0.99313 


3 50 


2.78 


2.76 


0.99006 


5 75 


4.58 


4.54 


0.99631 


1 30 


1.03 


1.03 


0.99306 


3 55 


2.82 


2.80 


0.98999 


5.80 


4.62 


4.58 


0.99623 


1 35 


1.07 


1.07 


0.99299 


3.60 


2.86 


2.84 


0.98993 


5 85 


4.66 


4.62 


0.99616 


1 40 


1.11 


1.11 


0.99292 


3 65 


2.90 


2.88 


0.98986 


5 90 


4.70 


4.66 


0.99608 


1.45 


1.15 


1.15 


0.99285 


3.70 


2.94 


2.92 


0.98980 


5.95 


4.74 


4.70 


0.99601 


1.50 


1.19 


1.19 


0.99278 


3 75 


2.98 


2.96 


0.98973 


6 00 


4.78 


4.74 


0.99594 


1.55 


1.23 


1.23 


0.99271 


3 80 


3.02 


3.00 


0.98967 


6.05 


4.82 


4.78 


0.99587 


1.60 


1.27 


1.26 


0.99264 


3 85 


3.06 


3.04 


0.98960 


6.10 


4.87 


4.82 


0.99579 


1.65 


1.31 


1.30 


0.99257 


3 90 


3.10 


3.08 


0.98954 


6.15 


4.91 


4.86 


0.99572 


1.70 


1.35 


1.34 


0.99250 


3 95 


3. 14 


3.12 


0.98947 


6.20 


4.95 


4.89 


0.99564 


1.75 


1.39 


1.38 


0.99243 


4.00 


3.18 


3.16 


0.98941 


6 25 


4.99 


4.93 


0.99557 


1.80 


1.43 


1.42 


0.99236 


4.05 


3.22 


3.20 


0.98934 


6 30 


5.03 


4.97 


0.99550 


1.85 


1.47 


1.46 


0.99229 


4.10 


3.26 


3.24 


0.98928 


6 35 


5.07 


5.01 


0.99543 


1.90 


1.51 


1.50 


0.99222 


4.15 


3.30 


3.28 


0.98921 


6 40 


5.11 


5.05 


0.99535 


1.95 


1.55 


1.54 


0.99215 


4.20 


3.34 


3.32 


0.98915 


6 45 


5.15 


5.09 


0.99528 


2.00 


1.59 


1.58 


0.99208 


4.25 


3.38 


3.36 


0.98908 


6 50 


5.19 


5.13 


0.99520 


2 05 


1.63 


1.62 


0.99201 


4 30 


3.42 


3.39 


0.98902 


6 55 


5.23 


5.17 


0.99513 


2 10 


1.67 


1.66 


0.99195 


4 35 


3.46 


3.43 


0.98895 


6.60 


5.27 


5.21 


0.99506 


2.15 


1.71 


1.70 


0.99188 


4.40 


3.50 


3.47 


0.98889 


6 65 


5.31 


5.25 


0.99499 


2.20 


1.75 


1.74 


0.99181 


4.45 


3.54 


3.51 


0.98882 


6.70 


5.35 


5.29 



XVI] 



WINES 



195 



5 






Table 


16. — Alcohol Table.— 


-Continued. 








SPECIFIC 


ALCOHOL 


SPECIFIC 
GRAVITY 


ALCOHOL 


SPECIFIC 


ALCOHOL 


QRA VITT 

20° C. 


Per cent 


Per 


Grams 


20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 


4° 


by volume 


Cent by 


per 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.98876 


6.75 


5.39 


5.33 


0.98566 


9.25 


7.41 


7.30 


0.98267 


11.75 


9.44 


9.28 


0.98870 


6 80 


5.43 


5.37 


0.98560 


9 30 


7.45 


7.34 


0.98261 


11.80 


9.48 


9.31 


0.98864 


6.85 


5.47 


5.41 


0.98554 


9 35 


7.49 


7.38 


0.98255 


11.85 


9.52 


9.35 


0.98857 


6.90 


5.51 


5.45 


0.98549 


9.40 


7.53 


7.42 


0.98250 


11.90 


9.56 


9.39 


0.98851 


6 95 


5.55 


5.49 


0.98543 


9.45 


7.57 


7.46 


0.98244 


11.95 


9.60 


9.43 


0.98845 


7.00 


5.59 


5.53 


0.98537 


9.50 


7.61 


7.50 


0.98238 


12.00 


9.64 


9.47 


0.98839 


7.05 


5.63 


5.57 


0.98531 


9.55 


7.65 


7.54 


0.98232 


12.05 


9.68 


9.51 


0.98832 


7.10 


5.67 


5.60 


0.98524 


9 60 


7.69 


7.58 


0.98226 


12.10 


9.72 


9.55 


0.98826 


7.15 


5.71 


5.64 


0.98518 


9 65 


7.73 


7.62 


0.98220 


12.15 


9.76 


9.59 


0.98820 


7.20 


5.75 


5.68 


0.98512 


9.70 


7.77 


7.66 


0.98214 


12.20 


9.80 


9.63 


0.98813 


7.25 


5.79 


5.72 


0.98506 


9.75 


7.81 


7.70 


0.98208 


12.25 


9.84 


9.67 


0.98806 


7 30 


5.83 


5.76 


0.98501 


9:80 


7.85 


7.73 


0.98203 


12.30 


9.89 


9.71 


0.98800 


7.35 


5.87 


5.80 


0.98495 


9.86 


7.89 


7.77 


0.98197 


12 35 


9.93 


9.75 


0.98794 


7.40 


5.91 


5.84 


0.98488 


9.90 


7.93 


7.81 


0.98191 


12.40 


9.97 


9.79 


0.98788 


7.45 


5.95 


5.88 


0.98482 


9.95 


7.97 


7.85 


0.98185 


12.45 


10.01 


9.83 


0.98781 


7.50 


5.99 


5.92 


0.98476 


10.00 


8.02 


7.89 


0.98180 


12.50 


10.05 


9.87 


0.98775 


7.55 


6.03 


5.96 


0.98470 


10.05 


8.06 


7.93 


0.98174 


12 55 


10.09 


9.91 


0.98769 


7 60 


6.07 


6.00 


0.98463 


10.10 


8.10 


7.97 


0.98168 


12.60 


10.13 


9.95 


0.98763 


7 65 


6.11 


6.04 


0.98457 


10.15 


8.14 


8.01 


0.98162 


12.65 


10.17 


9.99 


0.98756 


7.70 


6.15 


6.08 


0.98452 


10.20 


8.18 


8.05 


0.98156 


12.70 


10.21 


10.03 


0.98750 


7 75 


6.19 


6.12 


0.98446 


10.25 


8.22 


8.09 


0.98150 


12.75 


10.25 


10.07 


0.98744 


7.80 


6.24 


6.16 


0.98441 


10.30 


8.26 


8.13 


0.98145 


12.80 


10.29 


10.10 


0.98738 


7.85 


6.28 


6.20 


0.98435 


10.35 


8.30 


8.17 


0.98139 


12 85 


10.33 


10.14 


0.98731 


7.90 


6.32 


6.24 


0.98428 


10.40 


8.34 


8.21 


0.98132 


12.90 


10.38 


10.18 


0.98725 


7.95 


6.36 


6.28 


0.98422 


10.45 


8.38 


8.25 


0.98127 


12.95 


10.42 


10.22 


0.98718 


8 00 


6.40 


6.32 


0.98416 


10.50 


8.42 


8.29 


0.98122 


13 00 


10.46 


10.26 


0.98712 


8 05 


6.44 


6.36 


0.98410 


10.55 


8.46 


8.33 


0.98116 


13.05 


10.50 


10.30 


0.98706 


8 10 


6.48 


6.39 


0.98404 


10.60 


8.50 


8.37 


0.98111 


13.10 


10.54 


10.34 


0.98700 


8 15 


6.52 


6.43 


0.98398 


10.65 


8.64 


8.41 


0.98105 


13.15 


10.58 


10.38 


0.98694 


8.20 


6.56 


6.47 


0.98391 


10.70 


8.58 


8.45 


0.98100 


13.20 


10.62 


10.42 


0.98688 


8 25 


6.60 


6.51 


0.98385 


10.75 


8.62 


8.49 


0.98094 


13 25 


10.66 


10.46 


0.98682 


8 30 


6.64 


6.55 


0.98379 


10.80 


8.66 


8.52 


0.98089 


13 30 


10.70 


10.50 


0.98676 


8 35 


6.68 


6.59 


0.98373 


10.85 


8.70 


8.56 


0.98083 


13 35 


10.74 


10.54 


0.98670 


8 40 


6.72 


6.63 


0.98368 


10.90 


8.75 


8.60 


0.98077 


13.40 


10.78 


10.58 


0.98664 


8 45 


6.76 


6.67 


0.98362 


10.95 


8.79 


8.64 


0.98071 


13.45 


10.82 


10.62 


0.98658 


8 50 


6.80 


6.71 


0.98356 


11.00 


8.83 


8.68 


0.98066 


13 50 


10.86 


10.66 


0.98652 


8.55 


6.84 


6.75 


0.98350 


11.05 


8.87 


8.72 


0.98060 


13 55 


10.90 


10.70 


0.98646 


8 60 


6.88 


6.79 


0.98344 


11.10 


8.91 


8.76 


0.98054 


13.60 


10.95 


10.74 


0.98640 


8 65 


6.92 


6.83 


0.98338 


11.15 


8.95 


8.80 


0.98048 


13 65 


10.99 


10.78 


0.98633 


8.70 


6.96 


6.87 


0.98332 


11.20 


8.99 


8.84 


0.98043 


13.70 


11.03 


10.81 


0.98627 


8.75 


7.00 


6.91 


0.98326 


11.25 


9.03 


8.88 


0.98037 


13.75 


11.07 


10.85 


0.98620 


8 80 


7.04 


6.95 


0.98320 


U.30 


9.07 


8.92 


0.98031 


13.80 


11.11 


10.89 


0.98614 


8 85 


7.08 


6.99 


0.98314 


11.35 


9.11 


8.96 


0.98025 


13.85 


11.15 


10.93 


0.98608 


8 90 


7.12 


7.03 


0.98308 


11.40 


9.15 


9.00 


0.98020 


13.90 


11.19 


10.97 


0.98602 


8.95 


7.16 


7.07 


0.98302 


11.45 


9.19 


9.04 


0.98014 


13.95 


11.23 


11.01 


0.98596 


9.00 


7.20 


7.10 


0.98296 


11.50 


9.23 


9.08 


0.98009 


14.00 


11.28 


11.05 


0.98500 


9.05 


7.24 


7.14 


0.98290 


11.65 


9.27 


9.12 


0.98003 


14.05 


11.32 


11.09 


0.98584 


9.10 


7.29 


7.18 


0.98285 


11.60 


9.32 


9.16 


0.97998 


14.10 


11.36 


11.13 


0.98578 


9 15 


7.33 


7.22 


0.98279 


11.65 


9.36 


9.20 


0.97992 


14.15 


11.40 


11.17 


0.98572 


9.20 


7.37 


7.26 


0.98273 


11.70 


9.40 


9.24 


0.97986 


14.20 


11.44 


11.21 



196 



METHODS OF ANALYSIS 



[Chap. 



5 






Table 16.— Alcohol Table. - 


-Continued. 








SPECIFIC 


ALCOHOL 


SPECIFIC 

GRAVITY 

20° C. 

4° 


ALCOHOL 


SPECIFIC 
GRAVITY 
20° C. 
4° 


ALCOHOL 


20° C. 
4° 


Per cent 

by volume 

at 20° C. 


Per 
cent by 
weight 


Grams 

per 
100 cc. 


Per cent 
by volume 
at 20° C. 


Per 
cent by 
weight 


Grams 

per 
100 cc. 


Per cent 
by volume 
at 20° C. 


Per 

cent by 
weight 


Grams 

per 
100 cc. 


0.97980 
0.97975 
0.97969 
0.97964 
0.97958 


14.25 
14.30 
14.35 
14.40 
14.45 


1148 
11.52 
11.56 
11.60 
11.64 


11.25 
11.29 
11.33 
11.37 
11.41 


0.97704 
0.97699 
0.97694 
0.97689 
0.97683 


16.75 
16.80 
16.86 
16.90 
16.95 


13.53 
13.57 
13.61 
13.66 
13.70 


13.22 
13.26 
13.30 
13.34 
13.38 


0.97438 
0.97433 
0.97428 
0.97423 
0.97417 


19.26 
19.30 
19 35 
19.40 
19.45 


15.59 
15.64 
15.68 
15.72 
15.76 


15.20 
15.23 
15.27 
15.31 
15.35 


0.97953 
0.97947 
0.97942 
0.97936 
0.97930 


14.50 
14 55 
14.60 
14 65 
14.70 


11.68 
11.72 
11.77 
11.81 
11.85 


11.44 
11.48 
11.52 
11.56 
11.60 


0.97678 
0.97672 
0.97667 
0.97661 
0.97656 


17.00 
17.05 
17.10 
17.15 
17.20 


13.74 
13.78 
13.82 
13.86 
13.90 


13.42 
13.46 
13.50 
13.54 
13.58 


0.97412 
0.97407 
0.97402 
0.97396 
0.97391 


19.50 
19.56 
19.60 
19.65 
19.70 


15.80 
15.84 
15.88 
15.92 
15.97 


15.39 
15.43 
15.47 
15.51 
15.55 


0.97924 
0.97919 
0.97913 
0.97908 
0.97902 


14.75 
14 80 
14.85 
14.90 
14.96 


11.89 
11.93 
11.97 
12.01 
12.06 


11.64 
11.68 
11.72 
11.76 
11.80 


0.97650 
0.97645 
0.97639 
0.97634 
0.97629 


17 26 
17.30 
17 35 
17.40 
17.46 


13.94 
13.98 
14-02 
14.07 
14-11 


13.62 
13.66 
13.70 
13.74 
13.78 


0.97386 
0.97381 
0.97375 
0.97370 
0.97364 


19.75 
19.80 
19.85 
19.90 
19.96 


16.01 
16.05 
16.09 
16.13 
16.17 


15.59 
15.63 
15.67 
15.71 
15.75 


0.97897 
0.97891 
0.97885 
0.97879 
0.97874 


15.00 
15 05 
15.10 
15.15 
15.20 


12.09 
12.13 
12.18 
12.22 
12.26 


11.84 
11.88 
11.92 
11.96 
12.00 


0.97624 
0.97618 
0.97613 
0.97607 
0.97602 


17.60 
17 55 
17.60 
17.65 
17.70 


14-15 
14.19 
14-23 
14-27 
14-31 


13.81 
13.85 
13.89 
13.93 
13.97 


0.97359 
0.97354 
0.97349 
0.97344 
0.97339 


20.00 
20.05 
20 10 
20.16 
20.20 


16.21 
16.25 
16.30 
16.34 
16.38 


15.79 
15.83 
15.87 
15.91 
15.95 


0.97868 
0.97863 
0.97857 
0.97852 
0.97846 


15 25 
15 30 
15 36 
15 40 
15.45 


12.30 
12.34 
12.38 
12.42 
12.46 


12.04 
12.08 
12.12 
12.16 
12.20 


0.97596 
0.97591 
0.97586 
0.97581 
0.97575 


17.75 
17.80 
17.85 
17.90 
17.95 


14-35 
14-40 
14-44 
14-48 
14-52 


14.01 
14.05 
14.09 
14.13 
14.17 


0.97333 
0.97328 
0.97322 
0.97317 
0.97311 


20.26 
20.30 
20.35 
20.40 
20.45 


16. 42 
16.46 
16.50 
16.55 
16.59 


15.99 
16.02 
16.06 
16.10 
16.14 


0.97841 
0.97835 
0.97830 
0.97824 
0.97819 


16 60 
15 65 
16.60 
15 65 
16.70 


12.50 
12.54 
12.59 
12.63 
12.67 


12.23 
12.27 
12.31 
12.35 
12.39 


0.97570 
0.97564 
0.97559 
0.97553 
0.97548 


18 00 
18.05 
18 10 
18.15 
18.20 


14-56 
14-60 
14-64 
14-68 
14-73 


14.21 
14.25 
14.29 
14.33 
14.37 


0.97306 
0.97300 
0.97295 
0.97289 
0.97284 


20.60 
20.56 
20 60 
20.66 
20.70 


16.63 
16.67 
16.71 
16.75 
16.80 


16.18 
16.22 
16.26 
16.30 
16.34 


0.97813 
0.97808 
0.97802 
0,97797 
0.97791 


15 75 
15 80 
15 85 
15 90 
15.95 


12.71 
12.75 
12.79 
12.83 
12.87 


12.43 
12.47 
12.51 
12.55 
12.59 


0.97542 
0.97538 
0.97532 
0.97527 
0.97522 


18 25 
18.30 
18 35 
18.40 
18.45 


14-77 
14-81 
14-85 
14.89 
14.93 


14.41 
14.45 
14.49 
14.52 
14.56 


0.97278 
0.97273 
0.97268 
0.97263 
0.97257 


20 76 
20.80 
20.85 
20.90 
20 95 


16.84 
16.88 
16.92 
16.96 
17.00 


16.38 
16.42 
16.46 
16.50 
16.54 


0.97786 
0.97780 
0.97775 
0.97769 
0.97764 


16 00 
16.05 
16.10 
16.15 
16 20 


12.92 
12.96 
13.00 
13.04 
13.08 


12.63 
12.67 
12.71 
12.75 
12.79 


0.97517 
0.97512 
0.97507 
0.97501 
0.97496 


18.50 
18.55 
18 60 
18.65 
18.70 


14-97 
15.01 
15.06 
15.10 
15.14 


14.60 
14.64 
14.68 
14.72 
14.76 


0.97252 
0.97247 
0.97242 
0.97237 
0.97232 


21 00 
21.05 
21.10 
21.15 
21.20 


17.04 
17.08 
17.13 
17.17 
17.21 


16.58 
16.62 
16.66 
16.70 
16.73 


0.97758 
0.97753 
0.97747 
0.97742 
0.97737 


16 26 
16.30 
16.35 
16 40 
16.45 


13.12 
13.16 
13.20 
13.24 
13.28 


12.83 
12.87 
12.91 
12.95 
12.99 


0.97490 
0.97485 
0.97479 
0.97474 
0.97469 


18.76 
18 80 
18 85 
18.90 
18 96 


15.18 
15.22 
15.26 
15.30 
15.34 


14.80 
14.84 
14.88 
14.92 
14.96 


0.97227 
0.97222 
0.97216 
0.97210 
0.97204 


21.25 
21 30 
21.35 
21.40 
21.45 


17.25 
17.29 
17.33 
17.38 
17.42 


16.77 
16.81 
16.85 
16.89 
16.93 


0.97732 
0.97726 
0.97721 
0.97715 
0.97710 


16 50 
16 55 
16 60 
16 65 
16 70 


13.33 
13.37 
13.41 
13.45 
13.49 


13.02 
13.06 
13.10 
13.14 

13.18 


0.97464 
0.97459 
0.97454 
0.97449 
0.97444 


19.00 
19 05 
19 10 
19 15 
19 20 


15.39 
15.43 
15.47 
15.51 
15.55 


15.00 
15.04 
15.08 
15.12 
15.16 


0.97199 
0.97193 
0.97188 
0.97183 
0.97178 


21.60 
21.65 
21.60 
21.65 
21.70 


17.46 
17.50 
17.54 
17.58 
17.63 


16.97 
17.01 
17.05 
17.09 
17.13 



XVI] 



WINES 



197 



5 






Table 16.— Alcohol Table.- 


—Continued. 








SPECIFIC 


ALCOHOL 


SPECIFIC 
GRAVITY 


ALCOHOL 


SPECIFIC 


ALCOHOL 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


4" 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.97172 


21.75 


17.67 


17.17 


0.96896 


24.26 


19.75 


19.14 


0.96612 


26.76 


21.85 


21.12 


0.97167 


21 80 


17.71 


17.21 


0.96891 


24 30 


19.80 


19.18 


0.96606 


26 80 


21.90 


21.16 


0.97161 


21 85 


17.75 


17.25 


0.96885 


24 35 


19.84 


19.22 


0.96600 


26.85 


21.94 


21.20 


0.97156 


21.90 


17.79 


17.29 


0.96880 


24.40 


19.88 


19.26 


0.96595 


26 90 


21.98 


21.23 


0.97150 


21 95 


17.83 


17.33 


0.96874 


24.45 


19.92 


19.30 


0.96589 


26 96 


22.02 


21.27 


0.97145 


22 00 


17.88 


17.37 


0.96869 


24.50 


19.96 


19.34 


0.96583 


27 00 


22.07 


21.31 


0.97139 


22 05 


17.92 


17.41 


0.96863 


24,55 


20.00 


19.38 


0.96577 


27 05 


22.11 


21.35 


0.97134 


22 10 


17.96 


17.45 


0.96857 


24 60 


20.05 


19.42 


0.96571 


27.10 


22.15 


21.39 


0.97128 


22 15 


18.00 


17.49 


0.96851 


24.65 


20.09 


19.46 


0.96565 


27.16 


22.19 


21.43 


0.97123 


22 20 


18.04 


17.52 


0.96846 


24.70 


20.13 


19.50 


0.96559 


27.20 


22.24 


21.47 


0.97118 


22 25 


18.08 


17.56 


0.96840 


24.75 


20.17 


19.54 


0.96553 


27.26 


22.28 


21.51 


0.97113 


22 30 


18.13 


17.60 


0.96835 


24.80 


20.22 


19.58 


0.96548 


27 30 


22.32 


21.55 


0.97107 


22 35 


18.17 


17.64 


0.96829 


24 85 


20.26 


19.62 


0.96542 


27.36 


22.36 


21.59 


0.97102 


22 40 


18.21 


17.68 


0.96823 


24 90 


20.30 


19.66 


0.96536 


27.40 


22.40 


21.63 


0.97096 


22.45 


18.25 


17.72 


0.96817 


24.95 


20.34 


19.70 


0.96530 


27.46 


22.44 


21.67 


0.97091 


22 50 


18.29 


17.76 


0.96812 


25.00 


20.38 


19.73 


0.96525 


27.50 


22.49 


21.71 


0.97085 


22 55 


18.33 


17.80 


0.96806 


25.06 


20.42 


19.77 


0.96519 


27.66 


22.53 


21.75 


0.97080 


22 60 


18.38 


17.84 


0.96801 


25.10 


20.47 


19.81 


0.96513 


27.60 


22.57 


21.79 


0.97074 


22 65 


18.42 


17.88 


0.96795 


25.16 


20.51 


19,85 


0.96507 


27 66 


22.61 


21.83 


0.97069 


22.70 


18.46 


17.92 


0.96789 


25.20 


20.55 


19.89 


0.96501 


27.70 


22.66 


21.87 


0.97063 


22 75 


18.50 


17.96 


0.96783 


25 26 


20.59 


19.93 


0.96495 


27.75 


22.70 


21.91 


0.97058 


22 80 


18.54 


18.00 


0.96778 


26.30 


20.64 


19.97 


0.96489 


27.80 


22.74 


21.94 


0.97052 


22.85 


18.58 


18.04 


0.96772 


26 35 


20.68 


20.01 


0.96483 


27.86 


22.78 


21.98 


0.97047 


22 90 


18.63 


18.08 


0.96766 


26 40 


20.72 


20.05 


0.96477 


27.90 


22.83 


22.02 


0.97041 


22 95 


18.67 


18.12 


0.96760 


25.46 


20.76 


20.09 


0.96471 


27.96 


22.87 


22.06 


0.97036 


23 00 


18.71 


18.16 


0.96755 


26.60 


20.80 


20.13 


0.96465 


28 00 


22.91 


22.10 


0.97030 


23 05 


18.75 


18.20 


0.96749 


25.56 


20.84 


20.17 


0.96459 


28 05 


22.95 


22.14 


0.97025 


23 10 


18.79 


18.24 


0.96744 


25.60 


20.89 


20.21 


0.96454 


28,10 


23.00 


22.18 


0.97019 


23.15 


18.83 


18.28 


0.96738 


25 66 


20.93 


20.25 


0.96448 


28.15 


23.04 


22.22 


0.97013 


23.20 


18.88 


18.31 


0.96733 


26.70 


20.97 


20.29 


0.96442 


28.20 


23.08 


22.26 


0.97007 


23 25 


18.92 


18.35 


0.96727 


26 75 


21.01 


20.33 


0.96436 


28.25 


23.12 


22.30 


0.97002 


23 30 


18.96 


18.39 


0.96722 


26 80 


21.06 


20.37 


0.96430 


28 30 


23.17 


22.34 


0.96996 


23 36 


19.00 


18.43 


0.96716 


26 85 


21.10 


20.41 


0.96424 


28.36 


23.21 


22.38 


0.96991 


23 40 


19.04 


18.47 


0.96710 


25,90 


21.14 


20.44 


0.96418 


28.40 


23.25 


22.42 


0.96985 


23.45 


19.08 


18.51 


0.96704 


26.96 


21.18 


20.48 


0.96412 


28.45 


23.29 


22.46 


0.96980 


23 50 


19.13 


18.55 


0.96699 


26.00 


21.22 


20.52 


0.96406 


28.50 


23.33 


22.50 


0.96974 


23.55 


19.17 


18.59 


0.96693 


26 06 


21.26 


20.56 


0,96400 


28.56 


23.37 


22.54 


0.96969 


23 60 


19.21 


18.63 


0.96687 


26.10 


21.31 


20.60 


0.96393 


28 60 


23.42 


22.57 


0.96963 


23.65 


19.25 


18.67 


0.96681 


26.15 


21.35 


20.64 


0.96387 


28.66 


23.46 


22.61 


0.96958 


23.70 


19.29 


18.71 


0.96675 


26 20 


21.39 


20.68 


0.96381 


28.70 


23.51 


22.65 


0.96952 


23.75 


19.33 


18.75 


0.96669 


26.25 


21.43 


20.72 


0.96375 


28.76 


23.55 


22.69 


0.96947 


23.80 


19.38 


18.79 


0.96664 


26 30 


21.48 


20.76 


0.96369 


28.80 


23.59 


22.73 


0.96941 


23 85 


19.42 


18.83 


0.96658 


26.35 


21.52 


20.80 


0.96363 


28.86 


23.63 


22.77 


0.96936 


23 90 


19.46 


18.87 


0.96653 


26 40 


21.56 


20.84 


0.96357 


28.90 


23.67 


22.81 


0.96930 


23.95 


19.50 


18.91 


0.96647 


26 45 


21.60 


20.88 


0.96351 


28.95 


23.71 


22.85 


0.96925 


24 00 


19.55 


18.94 


0.96641 


26 50 


21.64 


20.92 


0.96346 


29 00 


23.76 


22.89 


0.96919 


24 05 


19.59 


18.98 


0.96635 


26,55 


21.68 


20.96 


0.96340 


29.05 


23.80 


22.93 


0.96913 


24.10 


19.63 


19.02 


0.96^0 


26 60 


21.73 


21.00 


0.96334 


29 10 


23.84 


22.97 


0.96907 


24.15 


19.67 


19.06 


0.96624 


26.65 


21.77 


21.04 


0.96328 


29.15 


23.88 


23.01 


0.96902 


24 20 


19.71 


19.10 


0.96618 


26 70 


21.81 


21.08 


0.96322 


29.20 


23.93 


23.05 



198 



METHODS OF ANALYSIS 



[Chap. 



5 






Table 16. — Alcohol Table.- 


—Continued. 








SPECIFIC 


ALCOHOL 


SPECIFIC 
GRAVITY 
20° C. 
4° 


ALCOHOL 


SPECIFIC 

GRAVITY 

20° C. 

4° 


ALCOHOL 


20° C. 
4° 


Per cent 
by volume 
at 20° C. 


Per 
cent by 
weight 


Grams 

per 
100 cc. 


Per cent 
by volume 
at 20° C. 


Per 
cent by 
weight 


Grams 

per 
100 cc. 


Per cent 

by volume 

at 20° C. 


Per 
cent by 
weight 


Grams 

per 
100 cc. 


0.96316 
0.96310 
0.96304 
0.96297 
0.96291 


29.25 
29 30 
29 35 
29 40 
29.45 


2S.97 
U.Ol 
24-05 
24-10 
24-14 


23.09 
23.13 
23.17 
23.21 
23.25 


0.96005 
0.95998 
0.95992 
0.95985 
0.95979 


31.75 
31.80 
31 85 
31.90 
31.95 


26.10 
26.15 
26.19 

26.23 
26.27 


25.06 
25.10 
25.14 
25.18 
25.22 


0.95669 
0.95662 
0.95655 
0.95648 
0.95641 


34.25 
34.30 
34.35 
34.40 
34.46 


28.26 
28.30 
28.34 
28.39 
28.43 


27.03 
27.07 
27.11 
27.15 
27.19 


0.96285 
0.96279 
0.96273 
0.96267 
0.96261 


29 50 
29 55 
29 60 
29 65 
29 70 


24 -IS 
24.22 
24-27 
24-31 
24-35 


23.29 
23.33 
23.36 
23.40 
23.44 


0.95972 
0.95965 
0.95958 
0.95952 
0.95945 


32 00 
32.05 
32.10 
32.15 
32.20 


26.32 
26.36 
26.41 
26.45 
26.49 


25.26 
25.30 
25.34 
25.38 
25.42 


0.95634 
0.95627 
0.95619 
0.95612 
0.95605 


34.60 
34.56 
34 60 
34.66 
34.70 


28.48 
28.52 
28.56 
28.60 
28.65 


27.23 
27.27 
27.31 
27.35 
27.39 


0.96255 
0.96248 
0.96242 
0.96236 
0.96230 


29.76 
29 80 
29 85 
29 90 
29.95 


24.39 

24-44 
24-48 
24-52 
24-56 


23.48 
23.52 
23.56 
23.60 
23.64 


0.95939 
0.95932 
0.95926 
0.95920 
9.95913 


32.25 
32 30 
32.35 
32 40 
32.46 


26.53 
26.58 
26.62 
26.66 
26.70 


25.46 
25.50 
25.54 
25.58 
25.61 


0.95598 
0.95591 
0.95584 
0.95577 
0.95570 


34.76 
34.80 
34.85 
34.90 
34 95 


28.69 
28.74 
28.78 
28.82 
28.86 


27.43 
27.47 
27.51 
27.55 
27.59 


0.96224 
0.96218 
0.96211 
0.96205 
0.96199 


30.00 
30 05 
30 10 
30 15 
30.20 


24.61 
24-65 
24-69 
24-73 
24-78 


23.68 
23.72 
23.76 
23.80 
23.84 


0.95906 
9.95900 
0.95893 
0.95887 
0.95880 


32.50 
32.65 
32 60 
32.65 
32.70 


26.75 
26.79 
26.83 
26.87 
26.92 


25.64 
25.68 
25.72 
25.76 
25.80 


0.95563 
0.95556 
0.95549 
0.95542 
0.95535 


35.00 
35.05 
36.10 
36.15 
36.20 


28.91 
28.95 
29.00 
29.04 
29.08 


27.63 
27.67 
27.71 

27.75 
27.78 


0.96193 
0.96187 
0.96181 
0.96175 
0.96169 


30 25 
30 30 
30 36 
30 40 
30.45 


24-82 
24-87 
24.91 
24.95 
24-99 


23.88 
23.92 
23.96 
24.00 
24.04 


0.95873 
0.95866 
0.95859 
0.95852 
0.95846 


32.76 
32.80 
32.85 
32 90 
32 95 


26.96 
27.01 
27.05 
27.09 
27.13 


25.84 
25.89 
25.93 
25.97 
26.01 


0.95528 
0.95521 
0.95513 
0.95506 
0.95499 


36.25 
35.30 
36.35 
35.40 
36.46 


29.12 
29.17 
29.21 
29.26 
29.30 


27.82 
27.86 
27.90 
27.94 
27.98 


0.96163 
0.96157 
0.96150 
0.96144 
0.96138 


30 50 
30 55 
30.60 
30 65 
30 70 


25.04 
25.08 

25.12 
25.16 
25.21 


24.08 
24.12 
24.15 
24.19 
24.23 


0.95839 
0.95833 
0.95826 
0.95819 
0.95812 


33.00 
33.05 
33.10 
33 15 
33.20 


27.18 
27.22 
27.27 
27.31 
27.35 


26.05 
26.09 
26.13 
26.17 
26.21 


0.95492 
0.95485 
95478 
0.95470 
0.95463 


36.50 
36 55 
36.60 
35.65 
36.70 


29.34 
29.38 
29.43 
29.47 
29.52 


28.02 
28.06 
28.10 
28.14 
28.18 


0.96132 
0.96125 
0.96119 
96112 
0.96106 


30.75 
30 80 
30 85 
30 90 
30 95 


25.25 
25.30 
25.34 
25.38 

25.42 


24.27 
24.31 
24,35 
24.39 
24.43 


0.95806 
0.95799 
0.95792 
0.95785 
0.95778 


33.26 
33 30 
33 35 
33.40 
33.45 


27.39 
27.44 
27.48 
27.52 
27.56 


26.25 
26.29 
26.33 
26.36 
26.40 


0.95456 
0.95449 
0.95441 
0.95434 
0.95426 


35.76 
36.80 

35 85 
36.90 

36 96 


29.56 
29.61 
29.65 
29.69 
29.73 


28.22 
28.26 
28.30 
28.34 
28.38 


0.96100 
0.96094 
0.96088 
0.96082 
0.96075 


31 00 
31.05 
31 10 
31.15 
31.20 


25.46 
25.50 
25.55 
25.59 
25.63 


24.47 
24.51 
24.55 
24.59 
24.63 


0.95771 
0.95764 
0.95757 
0.95751 
0.95745 


33.60 
33.65 
33.60 
33 65 
33.70 


27.61 
27.65 
27.70 

27.74 
27.78 


26.44 
26.48 
26.52 
26.56 
26.60 


0.95419 
0.95412 
0.95405 
0.95397 
0.95390 


36.00 
36.06 
36 10 
36.15 
36.20 


29.78 
29.82 
29.87 
29.91 
29.95 


28.42 
28.46 
28.49 
28.53 
28.57 


0.96069 
0.96062 
0.96056 
0.96049 
0.96043 


31.25 
31.30 
31.36 
31.40 
31.46 


25.67 
25.72 
25.76 
25.81 
25.85 


24.67 
24.71 
24.75 
24.79 
24.83 


0.95738 
0.95731 
0.95724 
0.95717 
0.95710 


33.75 
33.80 
33 85 
33.90 
33.95 


27.82 
27.87 
27.91 
27.96 
28.00 


26.64 
26.68 
26.72 
26.76 
26.80 


0.95382 
0.95375 
0.95367 
0.95360 
0.95353 


36.25 
36.30 
36.36 
36.40 
36.46 


29.99 
30.04 
30.09 
30.13 
30.17 


28.61 

28.65 
28.69 
28.73 
28.77 


0.96036 
0.96030 
0.96024 
0.96018 
0.96011 


31.50 
31.56 
31.60 
31.66 
31.70 


25.89 
25.93 
25.98 
26.02 
26.06 


24.86 
24.90 
24.94 
24.98 
25.02 


0.95703 
0.95696 
0.95689 
0.95682 
0.95675 


34.00 
34.05 
34,10 
34.16 
34.20 


28.04 
28.08 
28.13 
28.17 
28.22 


26.84 
26.88 
26.92 
26.96 
26.99 


0.95346 
0.95338 
0.95331 
0.95323 
0.95315 


36.50 
36.66 
36.60 
36.65 
36.70 


SO. 22 
30.26 
30.31 
30.35 
30.39 


28.81 
28.85 
28.89 
28.93 
28.97 



XVI] 



WINES 



199 



5 






Table 16.— Alcohol Table.- 


—Continued. 








spEcmc 


ALCOHOL 


SPECIFIC 


ALCOHOL 


SPECIFIC 


ALCOHOL 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 




at 20° C. 


weight 


100 cc. 




at20°C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.95308 


36,75 


30.43 


29.01 


0.94926 


39.25 


32.63 


30.99 


0.94519 


41.75 


84-86 


32.96 


0.95301 


36.80 


30.48 


29.05 


0.94918 


39.30 


32.68 


31.02 


0.94510 


41.80 


34-91 


33.00 


0.95294 


36 85 


30.52 


29.09 


0.94910 


39.35 


32.72 


31.06 


0.94502 


41.85 


84-95 


33.04 


0.95287 


36 90 


30.57 


29.13 


0.94901 


39.40 


32.77 


31.10 


0.94494 


41.90 


85.00 


33.07 


0.95279 


36 95 


30.61 


29.17 


0.94893 


39.45 


32.81 


31.14 


0.94486 


41.95 


35.04 


33.11 


0.95272 


37.00 


30.66 


29.21 


0.94885 


39.50 


32.86 


31.18 


0.94477 


42.00 


35.09 


33.15 


0.95264 


37.05 


30.70 


29.25 


0.94877 


39.55 


32.90 


31.22 


0.94469 


42.05 


35.18 


33.19 


0.95257 


37.10 


30.74 


29.29 


0.94869 


39 60 


82.95 


31.26 


0.94460 


42.10 


35.18 


33.23 


0.95249 


37.15 


30.78 


29.33 


0.94861 


39.65 


32.99 


31.30 


0.94452 


42.15 


35.22 


33.27 


0.95242 


37 20 


30.83 


29.36 


0.94853 


39.70 


33.04 


31.34 


0.94443 


42.20 


85.27 


33.31 


0.95234 


37.25 


30.87 


29.40 


0.94845 


39 75 


33.08 


31.38 


0.94435 


42.25 


35.31 


33.35 


0.95227 


37 30 


30.92 


29.44 


0.94837 


39 80 


33.13 


31.42 


0.94427 


42.30 


35.86 


33.39 


0.95219 


37 35 


30.96 


29.48 


0.94829 


39.85 


33.17 


31.46 


0.94419 


42.35 


35.40 


33.43 


0.95211 


37.40 


31.01 


29.52 


0.94821 


39 90 


83.22 


31.50 


0.94410 


42.40 


35.45 


33.47 


0.95203 


37.45 


31.05 


29.56 


0.94813 


39.95 


33.26 


31.54 


0.94402 


42.45 


35.49 


33.51 


0.95196 


37 50 


31.09 


29.60 


0.94805 


40.00 


33.80 


31.57 


0.94393 


42.50 


35.54 


33.55 


0.95188 


37 55 


31.13 


29.64 


0.94797 


40.05 


33.34 


31.61 


0.94385 


42.55 


85.58 


33.59 


0.95181 


37.60 


31.18 


29.68 


0.94789 


40.10 


33.39 


31.65 


0.94376 


42.60 


35.63 


33.63 


0.95173 


37 65 


31.22 


29.72 


0.94781 


40.15 


33.43 


31.69 


0.94368 


42.65 


35.67 


33.67 


0.95166 


37.70 


31.27 


29.76 


0.94773 


40.20 


38.48 


31.73 


0.94359 


42.70 


35.72 


33.71 


0.95158 


37.75 


31.31 


29.80 


0.94765 


40.25 


88.52 


31.77 


0.94351 


42.75 


85.76 


33.75 


0.95151 


37.80 


31.86 


29.84 


0.94757 


40.30 


83.57 


31.81 


0.94342 


42.80 


85.81 


33.78 


0.95143 


37 85 


31.40 


29.88 


0.94749 


40.35 


83.61 


31.85 


0.94334 


42.85 


85.85 


33.82 


0.95135 


37 90 


31.45 


29.92 


0.94741 


40.40 


33.66 


31.89 


0.94325 


42.90 


35.90 


33.86 


0.95127 


37.95 


31.49 


29.96 


0.94733 


40.45 


33.70 


31.93 


0.94317 


42.95 


35.94 


33.90 


0.95120 


38 00 


31.53 


29.99 


0.94725 


40.50 


38.75 


31.97 


0.94308 


43.00 


35.99 


33.94 


0.95112 


38 05 


31.57 


30.03 


U. 94717 


40.55 


38.79 


32.01 


0.94300 


43.05 


36.03 


33.98 


0.95104 


38.10 


31.62 


30.07 


0.94708 


40.60 


33.84 


32.05 


0.94291 


42.10 


86.08 


34.02 


0.95096 


38 15 


31.66 


30.11 


0.94700 


40.65 


38.88 


32.09 


0.94283 


43.15 


86.12 


34.06 


0.95089 


38.20 


31.71 


30.15 


0.94692 


40.70 


33.93 


32.13 


0.94274 


43.20 


36.17 


34.10 


0.95081 


38.25 


31.75 


30.19 


0.94684 


40.75 


33.97 


32.17 


0.94265 


43.25 


36.21 


34.14 


0.95074 


38 30 


31.80 


30.23 


0.94676 


40.80 


34.02 


32.20 


0.94256 


43 30 


86.26 


34.18 


0.95066 


38 35 


31.84 


30.27 


0.94668 


40.85 


34.06 


32.24 


0.94248 


43 35 


36.30 


34.22 


0.95058 


38 40 


31.89 


30.31 


0.94659 


40.90 


34-11 


32.28 


0.94239 


43.40 


36.35 


34.26 


0.95050 


38.45 


31.93 


30.35 


0.94651 


40.95 


34.15 


32.32 


0.94231 


43.45 


86.89 


34.30 


0.95043 


38.50 


31.97 


30.39 


0.94643 


41.00 


84-19 


32.36 


0.94222 


43.50 


36.44 


34.34 


0.95035 


38 55 


32.01 


30.43 


0.94635 


41.06 


34.23 


32.40 


0.94214 


43.55 


36.48 


34.38 


0.95027 


38 60 


32.06 


30.47 


0.94627 


41.10 


34-28 


32.44 


0.94205 


43 60 


36.53 


34.42 


0.95019 


38.65 


32.10 


30.51 


0.94619 


41.15 


34-32 


32.48 


0.94197 


43.65 


36.57 


34.46 


0.95011 


38 70 


32.15 


30.55 


0.94610 


41.20 


34-37 


32.52 


0.94188 


43.70 


36.62 


34.49 


0.95003 


38.75 


32.19 


30.59 


0.94602 


41.25 


34-41 


32.56 


0.94179 


43.75 


36.66 


34.53 


0.94996 


38.80 


32.24 


30.63 


0.94594 


41.30 


84-46 


32.60 


0.94170 


43.80 


36.71 


34.57 


0.94988 


38.85 


32.28 


30.67 


0.94586 


41.35 


34-50 


32.64 


0.94161 


43.85 


86.75 


34.61 


0.94980 


38 90 


32.33 


30.71 


0.94577 


41.40 


84-55 


32.68 


0.94152 


43.90 


36.80 


34.65 


0.94972 


38.95 


32.37 


30.75 


0.94569 


41.45 


84-59 


32.72 


0.94144 


43 95 


86.84 


34.69 


0.94964 


39 00 


32.42 


30.79 


0.94560 


41.50 


34-64 


32.76 


0.94135 


44 00 


86.89 


34.73 


0.94956 


39 05 


32.46 


30.83 


0.94552 


41 55 


84-68 


32.80 


0.94126 


44.05 


36.94 


34.77 


0.94949 


39.10 


32.51 


30.87 


0.94544 


41 60 


34-78 


32.84 


0.94117 


44.10 


36.99 


34.81 


0.94941 


39.15 


32.55 


30.91 


0.94536 


41.65 


84-77 


32.88 


0.94108 


44 15 


37.03 


34.85 


0.94934 


39 20 


32.59 


30.95 


0.94527 


41.70 


84.82 


32.92 


0.94099 


44.20 


87.08 


34.89 



200 



METHODS OF ANALYSIS 



[Chap. 



5 






Table 16.— Alcohol Table.- 


—Continued. 










ALCOHOL 






ALCOHOL 








ALCOHOL 




SPECIFIC 








SPECIFIC 








SPECIFIC 








GRAVITY 

20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


GR.^VIT Y 

20° C. 


Per cent 


1 Per 


Grams 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 




at 20° C. 


weight 


100 cc. 




at20°C. 


weight 


100 cc. 




at 20° C. 


weight 


100 CO. 


0.94091 


44.25 


37.12 


34.93 


0.93638 


46.75 


39.41 


36.90 


0.93164 


49.25 


41.72 


38.87 


0.940S2 


44 30 


37.17 


34.97 


0.93629 


46.80 


39.46 


36.94 


0.93155 


49 30 


41.77 


38.91 


0.94073 


44.35 


37.21 


35.01 


0.93619 


46 85 


39.50 


36.98 


0.93145 


49 35 


41.82 


38.95 


0.94064 


44.40 


37.26 


35.05 


0.93610 


46 90 


39.55 


37.02 


0.93136 


49.40 


41.87 


38.99 


0.94055 


44.45 


37.30 


35.09 


0.93600 


46 95 


39.59 


37.06 


0.93126 


49.46 


41.91 


39.03 


0.94046 


44.50 


37.35 


35.13 


0.93591 


47.00 


39.64 


37.10 


0.93116 


49.60 


41.96 


39.07 


0.94037 


44.55 


37.39 


35.17 


0.93582 


47.06 


39.68 


37.14 


0.93106 


49.55 


42.01 


39.11 


0.94028 


44 60 


37. U 


35.20 


0.93573 


47.10 


39.73 


37.18 


0.93096 


49.60 


42.06 


39.15 


0.94020 


44.65 


37.48 


35.24 


0.93563 


47.15 


39.77 


37.22 


0.93086 


49.65 


42.10 


39.19 


0.94011 


44 70 


37.53 


35.28 


0.93554 


47.20 


39.82 


37.26 


0.93076 


49.70 


42.15 


39.23 


0.94002 


44.75 


37.57 


35.32 


0.93545 


47.25 


39.87 


37.30 


0.93066 


49.75 


42.19 


39.27 


0.93993 


44 80 


37.62 


35.36 


0.93536 


47.30 


39.92 


37.34 


0.93056 


49.80 


42.24 


39.31 


0.93984 


44.85 


37.66 


35.40 


0.93526 


47.35 


39.96 


37.38 


0.93046 


49.86 


42.29 


39.35 


0.93975 


44.90 


37.71 


35.44 


0.93517 


47.40 


40.01 


37.42 


0.93036 


49 90 


42.34 


39.39 


0.93966 


44.96 


37.75 


35.48 


0.93507 


47.45 


40.05 


37.46 


0.93026 


49.95 


42.38 


39.43 


0.93957 


45.00 


37.80 


35.52 


0.93498 


47 50 


40.10 


37.49 


0.93017 


50 00 


42.43 


39.47 


0.93948 


45 05 


37.85 


35.56 


0.93488 


47.55 


40.14 


37.53 


0.93007 


50 05 


42.47 


39.51 


0.93939 


45.10 


37.90 


35.60 


0.93479 


47.60 


40.19 


37.57 


0.92997 


50.10 


42.52 


39.55 


0.93931 


45.15 


37.94- 


35.64 


0.93470 


47.65 


40.24 


37.61 


0.92987 


50.15 


42.57 


39.59 


0.93922 


46.20 


37.99 


35.68 


0.93461 


47.70 


40.29 


37.65 


0.92977 


50.20 


42.62 


39.63 


0.93912 


45.26 


38.03 


35.72 


0.93451 


47.75 


40.33 


37.69 


0.92967 


50 25 


42.66 


39.67 


0.93903 


45 30 


38.08 


35.76 


0.93442 


47.80 


40.38 


37.73 


0.92957 


50.30 


42.71 


39.70 


0.93894 


45 35 


38.12 


35.80 


0.93432 


47.85 


40.42 


37.77 


0.92947 


60 36 


42.76 


39.74 


0.93885 


45.40 


38.17 


35.84 


0.93423 


47.90 


40.47 


37.81 


0.92938 


60 40 


42.81 


39,78 


0.93876 


45.45 


38.21 


35.88 


0.93413 


47.95 


40.51 


37.85 


0.92928 


50.45 


42.85 


39.82 


0.93867 


45 50 


38.26 


35.92 


0.93404 


48.00 


40.56 


37.89 


0.92918 


50 50 


42.90 


39.86 


0.93858 


45 55 


38.30 


35.96 


0.93394 


48 05 


40.61 


37.93 


0.92908 


50.65 


42.94 


39.90 


0.93849 


45 60 


38.35 


35.99 


0.93385 


48 10 


40.66 


37.97 


0.92898 


50.60 


42.99 


39.94 


0.93840 


45.65 


38.39 


36.03 


0.93375 


48.15 


40.70 


38.01 


0.92888 


50 65 


43.04 


39.98 


0.93831 


45.70 


38.44 


36.07 


0.93366 


48.20 


40.75 


38.05 


0.92879 


60.70 


43.09 


40.02 


0.93822 


45.75 


38.49 


36.11 


0.93356 


48.26 


40.79 


38.09 


0.92869 


50.75 


43.13 


40.06 


0.93813 


45.80 


38.54 


36.15 


0.93347 


48 30 


40.84 


38.13 


0.92859 


50 80 


43.18 


40.10 


0.93803 


45 85 


38.58 


36.19 


0.93337 


48 35 


40.89 


38.17 


0.92849 


50 86 


43.23 


40.14 


0.93794 


45.90 


38.63 


36.23 


0.93328 


48.40 


40.94 


38.21 


0.92839 


50 90 


48.28 


40.18 


0.93785 


46.96 


38.67 


36.27 


0.93318 


48.45 


40.98 


38.25 


0.92829 


60.95 


43.32 


40.22 


0.93776 


46 00 


38.72 


36.31 


0.93308 


48.50 


41.03 


38.29 


0.92818 


51 00 


43.37 


40.26 


0.93767 


46 05 


38.76 


36.35 


0.93298 


48.55 


41.07 


38.33 


0.92808 


51.05 


43.42 


40.30 


0.93758 


46.10 


38.81 


36.39 


0.93289 


48 60 


41.12 


38.36 


0.92798 


61.10 


43.47 


40.34 


0.93749 


46.15 


38.85 


36.43 


0.93279 


48.65 


41.16 


38.40 


0.92788 


61.15 


43.51 


40.38 


0.93740 


46.20 


38.90 


36.47 


0.93270 


48.70 


41.21 


38.44 


0.92778 


51.20 


43.56 


40.42 


0.93730 


46.25 


38.95 


36.51 


0.93260 


48.75 


41.26 


38.48 


0.92768 


61 25 


43.60 


40.46 


0.93721 


46.30 


39.00 


36.55 


0.93251 


48 80 


41.31 


38.52 


0.92759 


61.30 


43.65 


40.49 


0.93712 


46 35 


39.04 


36.59 


0.93241 


48.85 


41.35 


38.56 


0.92749 


61 36 


43.70 


40.53 


0.93703 


46.40 


39.09 


36.63 


0.93232 


48 90 


41.40 


38.60 


0.92739 


51.40 


43.75 


40.57 


0.93693 


46.46 


39.13 


36.67 


0.93222 


48 95 


41-44 


38.64 


0.92729 


51.45 


43.79 


40.61 


0.93684 


46 50 


39.18 


36.70 


0.93213 


49.00 


41.49 


38.68 


0.92719 


51.60 


43.84 


40.65 


0.93675 


46.55 


39.22 


36.74 


0.93203 


49.06 


41.54 


38.72 


0.92709 


61.55 


43.89 


40,69 


0.93666 


46 60 


39.27 


36.78 


0.93194 


49 10 


41.59 


38.76 


0.92699 


51.60 


43.94 


40,73 


0.93656 


46 65 


39. '.n 


36.82 


0.93184 


49.15 


41.63 


38.80 


0,92689 


51.65 


43.98 


40.77 


0,93647 


46.70 


39.36 


36.86 


0.93174 


49 20 


41.68 


38.83 


0.92678 


51.70 


44.03 


40,81 



XVI] 



WINES 



201 



5 






Table 16.— Alcohol Table. - 


—Continued. 










ALCOHOL 








VLCOHOL 






AT.COHOT, 




SPECIFIC 








SPECIFIC 








SPECIFIC 








QRAVITT 
20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20-0. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 




at 20° C. 


weight 


100 cc. 




at 20° C 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.92668 


51.75 


U-08 


40.85 


0.92157 


54 25 


46.46 


42.82 


0.91629 


66 75 


48.89 


44.80 


0.92658 


51 80 


U.13 


40.89 


0.92147 


54 30 


46.51 


42.86 


0.91618 


56 80 


48.94 


44.83 


0.92648 


51 85 


U.17 


40.93 


0.92137 


54.35 


46.56 


42.90 


0.91608 


56 85 


48.98 


44.87 


0.92637 


51.90 


A^.22 


40.97 


0.92126 


54 40 


46.61 


42.94 


0.91597 


56 90 


49.03 


44.91 


0.92627 


51.95 


U.26 


41.01 


0.92116 


54.45 


46.66 


42.98 


0.91586 


56.95 


49.08 


44.95 


0.92617 


52.00 


U.31 


41.05 


0.92105 


54.50 


46.71 


43.02 


0.91575 


57.00 


49.1s 


44,99 


0.92607 


52.05 


U.S6 


41.09 


0.92095 


54.55 


46.75 


43.06 


0.91565 


57.06 


49.18 


45.03 


0.92597 


52.10 


U41 


41.13 


0.92084 


54 60 


46.80 


43.10 


0.91554 


•57.10 


49.23 


45.07 


0.92587 


52.15 


U46 


41.17 


0.92074 


54.66 


46.85 


43.14 


0.91543 


67.15 


49.28 


45.11 


0.92577 


52 20 


U.51 


41.20 


0.92063 


54.70 


46.90 


43.18 


0.91532 


57.20 


49.33 


45.15 


0.92567 


52 25 


U:55 


41.24 


0.92053 


54.75 


46.94 


43.22 


0.91521 


57.25 


49.38 


45.19 


0.92557 


52 30 


U-60 


41.28 


0.92042 


54 80 


46.99 


43.26 


0.91510 


57.30 


49.43 


45.23 


0.92547 


62 35 


U-65 


41.32 


0.92032 


54.85 


47.04 


43.30 


0.91500 


57 35 


49.47 


45.27 


0.92537 


52 40 


U.70 


41.36 


0.92021 


54.90 


47.09 


43.34 


0.91489 


57.40 


49.52 


45.31 


0.92527 


52.45 


U.74- 


41.40 


0.92011 


54.95 


47.14 


43.38 


0.91478 


57.46 


49.57 


45.35 


0.92516 


52 50 


U-79 


41.44 


0.92000 


55 00 


47.19 


43.42 


0.91467 


57 60 


49.62 


45.39 


0.92506 


52.55 


UM 


41.48 


0.91990 


55 06 


47.24 


43.46 


0.91457 


57.56 


49.67 


45.43 


0.92496 


52.60 


U.89 


41.52 


0.91979 


55.10 


47.29 


43.49 


0.91446 


57.60 


49.72 


45.47 


0.92486 


52 65 


U.9S 


41.56 


0.91969 


55 15 


47.33 


43.53 


0.91435 


57.66 


49.77 


45.51 


0.92476 


52.70 


44-98 


41.60 


0.91958 


55 20 


47.38 


43.57 


0.91424 


57.70 


49.82 


45.55 


0.92466 


52 75 


45.03 


41.64 


0.91948 


65.26 


47.43 


43.61 


0.91414 


57.75 


49.87 


45.59 


0.92455 


52.80 


45.08 


41.68 


0.91937 


65.30 


47.48 


43.65 


0.91403 


57.80 


49.92 


45.63 


0.92445 


52 85 


45.12 


41.72 


0.91927 


56 35 


47.53 


43.69 


0.91392 


57.85 


49.96 


45.67 


0.92434 


52.90 


45.17 


41.76 


0.91916 


55 40 


47.58 


43.73 


0.91381 


57.90 


50.01 


45.70 


0.92424 


52.95 


45.22 


41.80 


0.91906 


55.46 


47.62 


43.77 


0.91370 


57.96 


50.08 


45.74 


0.92414 


53 00 


45.27 


41.83 


0.91895 


55.50 


47.67 


43.81 


0.91359 


68.00 


50.11 


45.78 


0.92404 


53 05 


45.31 


41.87 


0.91885 


55 55 


47.72 


43.85 


0.91348 


68.05 


50.16 


45.82 


0.92394 


53.10 


45.36 


41.91 


0.91874 


55.60 


47.77 


43.89 


0.91337 


58.10 


50.21 


45.86 


0.92384 


53 15 


45.41 


41.95 


0.91864 


55 66 


47.82 


43.93 


0.91326 


58.16 


50.26 


45.90 


0.92373 


53.20 


45.46 


41.99 


0.91853 


65.70 


47.87 


43.97 


0.91315 


68.20 


50.31 


45.94 


0.92363 


53 25 


45.51 


42.03 


0.91842 


56.75 


47.91 


44.01 


0.91304 


58.25 


50.36 


45.98 


0.92353 


53 30 


45.56 


42.07 


0.91831 


55.80 


47.96 


44.04 


0.91293 


58.30 


50.41 


46.02 


0.92343 


53.35 


45.60 


42.11 


0.91821 


55 85 


48.01 


44.08 


0.91282 


58.36 


50.46 


46.06 


0.92332 


53.40 


45.65 


42.15 


0.91810 


55.90 


48.06 


44.12 


0.91271 


58.40 


50.51 


46.10 


0.92322 


53 45 


45.70 


42.19 


0.91800 


55.95 


48.11 


44.16 


0.91261 


58.45 


50.55 


46.14 


0.92312 


53 50 


45.75 


42.23 


0.91789 


66.00 


48.16 


44.20 


0.91250 


58 50 


50.60 


46.17 


0.92302 


53 55 


45.79 


42.27 


0.91779 


56.06 


48.20 


44.24 


0.91239 


58.55 


50.65 


46.21 


0.92291 


53 60 


45.84 


42.31 


0.91768 


56.10 


48.25 


44.28 


0.91228 


58.60 


50.70 


46.25 


0.92281 


53 65 


45.89 


42.35 


0.91758 


56.15 


48.30 


44.32 


0.91217 


58.65 


50.75 


46.29 


0.92271 


53 70 


45.94 


42.39 


0.91747 


66.20 


48.35 


44.36 


0.91206 


68.70 


50.80 


46.33 


0.92261 


53 75 


45.98 


42.43 


0.91736 


56 25 


48.40 


44.40 


0.91194 


58.76 


50.85 


46.37 


0.92250 


53.80 


46.03 


42.47 


0.91725 


56.30 


48.45 


44.44 


0.91183 


68.80 


50.90 


46.41 


0.92240 


53 85 


46.08 


42.51 


0.91715 


56.35 


48.50 


44.48 


0.91171 


58.85 


50.95 


46.45 


0.92230 


53.90 


46.13 


42.55 


0.91704 


56.40 


48.55 


44.52 


0.91160 


58.90 


51.00 


46.49 


0.92220 


53.95 


46.18 


42.59 


0.91694 


66.46 


48.59 


44.56 


0.91149 


58.95 


51.05 


46.53 


0.92209 


54.00 


46.23 


42.62 


0.91683 


56 50 


48.64 


44.60 


0.91138 


59.00 


51.10 


46.57 


0.92199 


54.05 


46.27 


42.66 


0.91672 


56.55 


48.69 


44.64 


0.91127 


59 05 


51.15 


46.61 


0.9218S 


54.10 


46.32 


42.70 


0.91661 


56 60 


48.74 


44.68 


0.91116 


59.10 


51.20 


46.65 


0.92178 


54.15 


46.36 


42.74 


0.91650 


56.65 


48.79 


44.72 


0.91104 


59.15 


51.25 


46.69 


0.92167 


54.20 


46.41 


42.78 


0.91639 


56.70 


48.84 


44.76 


0.91093 


59.20 


51.30 


46.73 



202 



METHODS OF ANALYSIS 



[Chap. 



5 






Table 16.— Alcohol Table.- 


—Continued. 










ALCOHOL 






ALCOHOL 








ALCOHOL 




SPECIFIC 








SPECIFIC 








SPECIFIC 








oravity 

20° c. 


Per cent 


Per 


Grama 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


4* 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.91082 


59.25 


61.35 


46.77 


0.90520 


61.75 


53.85 


48.74 


0.89942 


64.25 


56.39 


50.72 


0.91071 


59 30 


5140 


46.81 


0.90509 


61.80 


53.90 


48.78 


0.89930 


64.30 


56.44 


50.76 


0.91060 


59 35 


5145 


46.85 


0.90497 


61.85 


53.95 


48.82 


0.89918 


64.35 


66.49 


50.80 


0.91049 


59 40 


51.50 


46.89 


0.90486 


61.90 


54.00 


48.86 


0.89907 


64.40 


56.54 


50.83 


0.91038 


59.45 


51.55 


46.93 


0.90474 


61.95 


54.05 


48.90 


0.89895 


64.45 


66.59 


50.87 


0.91027 


59 50 


51.60 


46.97 


0.90463 


62.00 


54.10 


48.94 


0.89884 


64.60 


56.64 


50.91 


0.91016 


59 55 


51.65 


47.01 


0.90451 


62.05 


54.15 


48.98 


0.89872 


64 56 


56.70 


50.95 


0.91005 


59 60 


51.70 


47.05 


0.90440 


62.10 


54.20 


49.02 


0.89861 


64.60 


56.75 


50.99 


0.90993 


59.65 


51. TU 


47.09 


0.90428 


62 15 


54.25 


49.06 


0.89849 


64.65 


66.80 


51.03 


0.90982 


59 70 


51.79 


47.12 


0.90417 


62 20 


54.30 


49.10 


0.89837 


64.70 


56.85 


51.07 


0.90971 


59 75 


51.84- 


47.16 


0.90406 


62 25 


54.35 


49.14 


0.89825 


64.75 


56.90 


51.11 


0.90960 


59 80 


51.89 


47.20 


0.90395 


62.30 


54.40 


49.18 


0.89814 


64.80 


66.96 


51.15 


0.90949 


59 85 


51.94 


47.24 


0.90383 


62.35 


54.45 


49.22 


0.89802 


64.85 


57.00 


51.19 


0.90938 


59 90 


51.99 


47.28 


0.90372 


62 40 


54.50 


49.25 


0.89791 


64.90 


67.06 


51.23 


0.90926 


69.95 


52.04 


47.32 


0.90360 


62.45 


64.55 


49.29 


0.89779 


64.95 


67.11 


51.27 


0.90915 


60 00 


52.09 


47.36 


0.90349 


62.50 


5 4. 60 


49.33 


0.89767 


66.00 


57.16 


51.31 


0.90904 


60 05 


52.14 


47.40 


0.90337 


62.55 


54.66 


49.37 


0.89755 


65.05 


57.21 


51.35 


0.90893 


60 10 


52.19 


47.44 


0.90326 


62.60 


54.71 


49.41 


0.89744 


65.10 


67.26 


51.39 


0.90882 


60.15 


52.24 


47.48 


0.90314 


62 65 


54.76 


49.45 


0.89732 


65.16 


67.31 


51.43 


0.90871 


60 20 


52.29 


47.52 


0.90302 


62.70 


54. 81 


49.49 


0.89720 


65.20 


57.36 


51.47 


0.90859 


60 25 


52. n 


47.56 


0.90290 


62 75 


54.86 


49.53 


0.89708 


65 25 


57.41 


51.51 


0.90848 


60 30 


52.39 


47.60 


0.90279 


62 80 


54.91 


49.57 


0.89696 


65 30 


57.46 


51.55 


0.90837 


60 35 


52.44 


47.64 


0.90267 


62 85 


64.96 


49.61 


0.89684 


66 36 


57.52 


51.59 


0.90826 


60 40 


52.49 


47.68 


0.90256 


62.90 


66.01 


49.65 


0.89672 


65.40 


57.57 


51.63 


0.90814 


60 45 


52.54 


47.72 


0.90244 


62.95 


55.06 


49.69 


0.89660 


66.46 


57.62 


51.67 


0.90803 


60 50 


52.59 


47.76 


0.90233 


63 00 


55.11 


49.73 


0.89649 


66 50 


57.67 


51.71 


0.90792 


60 55 


52.64 


47.80 


0.90221 


63 05 


65.16 


49.77 


0.89637 


65 55 


67.72 


51.75 


0.90781 


60 60 


62.69 


47.84 


0.90210 


63.10 


56.21 


49.81 


0.89626 


65.60 


57.77 


51.78 


0.90769 


60 65 


52.74 


47.88 


0.90198 


63.15 


55.26 


49.85 


0.89614 


66 65 


57.83 


51.82 


0.90758 


60.70 


52.79 


47.91 


0.90187 


63 20 


56.31 


49.89 


0.89602 


65.70 


57.88 


51.86 


0.90747 


60 75 


52.84 


47.95 


0.90175 


63 25 


66.37 


49.93 


0.89590 


66 76 


57.93 


51.90 


0.90736 


60 80 


52.89 


47.99 


0.90163 


63 30 


65.42 


49.97 


0.89578 


65.80 


57.98 


51.94 


0.90724 


60 85 


52.94 


48.03 


0.90151 


63 35 


55.47 


50.01 


0.89566 


66 86 


58.04 


51.98 


0.90713 


60 90 


52.99 


48.07 


0.90140 


63.40 


56.52 


50.04 


0.89554 


66.90 


58.09 


52.02 


0.90701 


60 95 


53.04 


48.11 


0.90128 


63 45 


65.57 


50.08 


0.89542 


65 95 


58.14 


52.06 


0.90690 


61 00 


53.09 


48.15 


0.90117 


63 50 


66.62 


50.12 


0.89531 


66 00 


58.19 


52.10 


0.90678 


61 05 


53.14 


48.19 


0.90105 


63.55 


55.67 


50.16 


0.89519 


66.05 


58.24 


52.14 


0.90667 


61.10 


53.19 


48.23 


0.90094 


63.60 


55.72 


50.20 


0.89507 


66.10 


58.29 


52.18 


0.90656 


61.15 


53.24 


48.27 


0.90082 


63.65 


55.77 


50.24 


0.89495 


66.15 


58.35 


52.22 


0.90645 


61 20 


53.29 


48.31 


0.90070 


63.70 


56.82 


50.28 


0.89483 


66.20 


58.40 


52.26 


0.90633 


61.25 


53.34 


48.35 


0.90059 


63.75 


55.88 


50.32 


0.89471 


66.26 


58.46 


52.30 


0.90622 


61 30 


53.39 


48.39 


0.90048 


63.80 


55.93 


50.36 


0.89459 


66.30 


58.50 


52.33 


0.90610 


61.35 


53.44 


48.43 


0.90036 


63.85 


55.98 


50.40 


0.89447 


66.35 


58.66 


52.37 


0.90599 


61.40 


53.49 


48.47 


0.90025 


63.90 


56.03 


50.44 


0.89435 


66.40 


68.60 


52.41 


0.90588 


61.45 


53.55 


48.51 


0.90013 


63.95 


56.08 


50.48 


0.89423 


66.45 


68.66 


52.45 


0.90577 


61.50 


53.60 


48.55 


0.90001 


64.00 


56.13 


50.52 


0.89411 


66 50 


58.71 


52.49 


0.90565 


61.55 


63.65 


48.59 


0.89989 


64.05 


56.18 


50.56 


0.89399 


66 55 


58.76 


52.53 


0.90554 


61.60 


53.70 


48.62 


0.89978 


64.10 


56.23 


50.60 


0.80387 


66.60 


58.81 


52.57 


0.90543 


61.65 


53.75 


48.66 


0.89966 


64.15 


56.29 


50.64 


0.89375 


66 65 


68.87 


52.61 


0.90532 


61.70 


53.80 


48.70 


0.89954 


64.20 


66.34 


50.68 


0.89363 


66.70 


68.92 


52.65 



XVI] 



WINES 



203 



5 






Tab 


LE 16.— Alcohol Table 


.— Cont 


inued. 










ALCOHOL 






ALCOHOL 






ALCOHOL 




SPECIFIC 








SPECIFIC 








SPECIFIC 








GRAVITY 

20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


4° 


by volume 


cent by 


per 


4° 


by volume cent by 


per 


4° 


by volume 


cent by 


per 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.89351 


66 75 


58.97 


52.69 


0.88744 


69.25 


61.60 


54.66 


0.88120 


71.76 


64-27 


56.64 


0.89339 


66 80 


59.02 


52.73 


0.88732 


69 30 


61.65 


54.70 


0.88107 


71 80 


64.32 


56.68 


0.89327 


66 85 


59.07 


52.77 


0.88720 


69 35 


61.70 


54.74 


0.88094 


71 85 


64.38 


56.72 


0.89315 


66 90 


59.12 


52.81 


0.88707 


69 40 


61.75 


54.78 


0.88081 


71 90 


64-43 


56.75 


0.89303 


66 95 


59.18 


52.85 


0.88695 


69 45 


61.81 


54.82 


0.88069 


71 95 


64-49 


56.79 


0.89291 


67.00 


59.23 


52.89 


0.88682 


69 60 


61.86 


54.86 


0.88056 


72 00 


64-54 


56.83 


0.89279 


67 05 


59.28 


52.93 


0.88670 


69 55 


61.92 


54.90 


0,88044 


72 06 


64-60 


56.87 


0.89267 


67 10 


59.33 


52.97 


0.88658 


69 60 


61.97 


54.94 


0,88031 


72 10 


64-65 


56.91 


0.89255 


67.15 


59.39 


53.01 


0.88646 


69 65 


62.02 


54.98 


0.88018 


72 15 


64.71 


56.95 


0.89243 


67 20 


59. U 


53.04 


0.88633 


69 70 


62.07 


55.02 


0.88005 


72 20 


64.76 


56.99 


0.89231 


67 25 


59.49 


53,08 


0.88621 


69.75 


62.13 


55.06 


0,87993 


72 25 


64-82 


57.03 


0.89219 


67 30 


59.54 


53.12 


0.88608 


69 80 


62.18 


55.10 


0,87980 


72 30 


64.87 


57.07 


0.89207 


67 35 


59.60 


53.16 


0.88596 


69 86 


62.24 


55.14 


0.87967 


72 35 


64-93 


57.11 


0.89195 


67 40 


59.65 


53.20 


0.88583 


69 90 


62.29 


55.18 


0.87954 


72 40 


64-98 


57.15 


0.89183 


67.45 


59.70 


53.24 


0.88571 


69 95 


62.34 


55.22 


0.87942 


72 46 


65.03 


57.19 


0.89171 


67 50 


59.75 


53.28 


0.88558 


70 00 


62.39 


55.25 


0.87929 


72.60 


65.08 


57.23 


0.89159 


67 55 


59.81 


53.32 


0.88546 


70 05 


62.45 


55.29 


0.87916 


72 55 


65.14 


57.27 


0.89147 


67 60 


59.86 


53.36 


0.88533 


70 10 


62.50 


55,33 


0.87903 


72 60 


65.19 


57.31 


0.89135 


67 65 


59.91 


53.40 


0.88521 


70 15 


62.56 


55.37 


0.87891 


72.65 


65.25 


57.35 


0.89122 


67 70 


59.96 


53.44 


0.88508 


70.20 


62.61 


55.41 


0.87878 


72 70 


65.30 


57.38 


0.89110 


67 75 


60.02 


53.48 


0.88496 


70 25 


62.66 


55.45 


0.87865 


72 75 


65.36 


57.42 


0.89098 


67 80 


60.07 


53.52 


0.88484 


70 30 


62.71 


55.49 


0.87852 


72 80 


65.41 


57.46 


0.89086 


67 85 


60.12 


53.56 


0.88472 


70 35 


62.77 


55,53 


0.87839 


72 86 


65.47 


57.50 


0.89074 


67 90 


60.17 


53.60 


0.88459 


70.40 


62.82 


55.57 


0.87826 


72 90 


65.52 


57.54 


0.89062 


67 95 


60.23 


53.64 


0.88447 


70 46 


62.87 


55.61 


0.87813 


72 95 


65.58 


57.58 


0.89050 


68 00 


60.28 


53.68 


0.88434 


70 50 


62.92 


55,65 


0.87800 


73 00 


65.63 


57.62 


0.89038 


68 05 


60.33 


53.72 


0.88422 


70 56 


62.98 


55.69 


0.87788 


73 05 


65.69 


57.66 


0.89026 


68 10 


60.38 


53.75 


0.88409 


70 60 


63.03 


55.73 


0.87775 


73.10 


65.74 


57.70 


0.89014 


68 15 


60.44 


53.79 


0.88397 


70 66 


63.09 


55.77 


0.87762 


73 16 


65.80 


57.74 


0.89001 


68 20 


60.49 


53.83 


0.88384 


70.70 


63.14 


55.81 


0.87749 


73 20 


65.85 


57.78 


0.88989 


68 25 


60.54 


53.87 


0.88372 


70 75 


63.20 


55.85 


0.87737 


73 25 


65.91 


57.82 


0.88977 


68 30 


60.59 


53.91 


0.88359 


70 80 


63.25 


55,89 


0.87724 


73.30 


65.96 


57.86 


0.88965 


68 35 


60.65 


53.95 


0.88347 


70 85 


63.31 


55.93 


0.87711 


73 36 


66.02 


57.90 


0.88952 


68 40 


60.70 


53.99 


0.88334 


70 90 


63.36 


55.97 


0.87698 


73 40 


66.07 


57.94 


0.88940 


68 45 


60.75 


54.03 


0.88322 


70 95 


63.41 


56.01 


0,87685 


73 46 


66.13 


57.98 


0.88928 


68 50 


60.80 


54.07 


0.88309 


71.00 


63.46 


56.04 


0.87672 


73 50 


66.18 


58.02 


0.88916 


68 55 


60.86 


54.11 


0.88297 


71 06 


63.52 


56.08 


0.87659 


73 55 


66.23 


58.06 


0.88904 


68 60 


60.91 


54.15 


0.88284 


71 10 


63.57 


56.12 


0.87646 


73 60 


66.28 


58.10 


0.88892 


68.65 


60.96 


54.19 


0.88272 


71.16 


63.63 


56.16 


0.87633 


73 66 


66.34 


58.14 


0.88879 


68.70 


61.01 


54.23 


0.88259 


71 20 


63.68 


56.20 


0.87620 


73.70 


68.39 


58.17 


0.88867 


68.75 


61.07 


54.27 


0.88246 


71 25 


63.74 


56.24 


0.87607 


73.75 


66.45 


58.21 


0.88854 


68 80 


61.12 


54.31 


0.88233 


71 30 


63.79 


56.28 


0.87594 


73 80 


66.50 


58.25 


0.88842 


68 85 


61.17 


54.35 


0.88221 


71 35 


63.84 


56.32 


0.87581 


73 86 


66.56 


58.29 


0.88830 


68 90 


61.22 


54.39 


0.88208 


71 40 


63.89 


56,36 


0.87568 


73.90 


66.61 


58.33 


0.88818 


68 96 


61.28 


54.43 


0.88196 


71 45 


63.95 


56.40 


0.87555 


73 96 


66.67 


58.37 


0.88805 


69 00 


61.33 


54.47 


0.88183 


71 50 


6 4. 00 


56.44 


0.87542 


74.00 


66. 7. i 


58.41 


0.88793 


69.05 


61.39 


54.51 


0.88171 


71.55 


64.06 


56.48 


0.87529 


74.05 


66 . 7S 


58.45 


0.88781 


69 10 


61.44 


54.54 


0.88158 


71.60 


64.11 


56.52 


0.87516 


74 10 


66.83 


58.49 


0.88769 


69.15 


61.49 


54.58 


0.88145 


71 65 


64.17 


56.56 


0.87504 


74.16 


66.89 


58.53 


0.88756 


69 20 


61.54 


54.62 


0.88132 


71.70 


64.22 


56.60 


0.87491 


74 20 


66.94 


58.57 



204 



METHODS OF ANALYSIS 



[Chap. 



5 






Table 16.— Alcohol Table.- 


—Continued. 










AI.COHOT. 






ALCOHOL 






ALCOHOL 




SPECIFIC 








SPECIFIC 








SPECIFIC 








GRAVITY 
20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


4° 


by volume 


cent by 


per 


4° 


by volume cent by 


per 


4° 


by volume 


cent by 


per 




at 20° C. 


weight 


100 cc. 




at20°C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.87478 


74 25 


67.00 


58.61 


0.86818 


76.75 


69.78 


60.58 


0.86137 


79.25 


72.63 


62.56 


0.87465 


74.30 


67.05 


58.65 


0.86805 


76.80 


69.84 


60.62 


0.86124 


79.30 


72.68 


62.60 


0.87452 


74 35 


67.11 


58.69 


0.86791 


76.85 


69.90 


60.66 


0.86110 


79 35 


72.74 


62.64 


0.87439 


74.40 


67.16 


58.73 


0.86778 


76.90 


69.95 


60.70 


0.86096 


79.40 


72.80 


62.67 


0.87426 


74.45 


67.22 


58.77 


0.86764 


76 95 


70.01 


60.74 


0.86082 


79.45 


72.86 


62.71 


0.87413 


74.50 


67.27 


58.81 


0.86751 


77.00 


70.06 


60.78 


0.86069 


79.50 


72.91 


62.75 


0.87400 


74.55 


67.33 


58.85 


0.86737 


77.05 


70.12 


60.82 


0.86055 


79 55 


72.97 


62.79 


0.87387 


74.60 


67.38 


58.89 


0.86724 


77.10 


70.18 


60.86 


0.86041 


79 60 


73.03 


62.83 


0.87373 


74.65 


67. U 


58.93 


0.86710 


77.15 


70.24 


60.90 


0.86027 


79.65 


73.09 


62.87 


0.87360 


74.70 


67.49 


58.97 


0.86697 


77.20 


70.29 


60.94 


0.86013 


79.70 


73.14 


62.91 


0.87347 


74.75 


67.55 


59.01 


0.86684 


77.25 


70.35 


60.98 


0.85999 


79 75 


73.20 


62.95 


0.87334 


74.80 


67.61 


59.04 


0.86671 


77 30 


70.40 


61.02 


0.85984 


79.80 


73.26 


62.99 


0.87321 


74.85 


67.67 


59.08 


0.86657 


77.35 


70.46 


61.06 


0.85970 


79 85 


73.32 


63.03 


,0.87308 


74.90 


67.72 


59.12 


0.86644 


77.40 


70.51 


61.10 


0.85956 


79 90 


73.37 


63.07 


0.87295 


74.95 


67.78 


59.16 


0.86630 


77.45 


70.57 


61.14 


0.85942 


79.95 


73.43 


63.11 


0.87282 


75.00 


67.83 


59.20 


0.86617 


77 50 


70.63 


61.18 


0.85928 


80 00 


73.49 


63.15 


0.87269 


75.05 


67.89 


59.24 


0.86603 


77.55 


70.69 


61.22 


0.85914 


80 05 


73.55 


63.19 


0.87256 


75.10 


67.94- 


59.28 


0.86589 


77.60 


70.74 


61.25 


0.85901 


80.10 


73.60 


63.23 


.0.87243 


75.15 


68.00 


59.32 


0.86575 


77 65 


70.80 


61.29 


0.85887 


80 15 


73.66 


63.27 


0.87230 


75.20 


68.05 


59.36 


0.86562 


77.70 


70.85 


61.33 


0.85873 


80.20 


73.72 


63.30 


0.87217 


75 25 


68.11 


59.40 


0.86548 


77.75 


70.91 


61.37 


0.85859 


80.25 


73.78 


63.34 


,0.87204 


75.30 


68.16 


59.44 


0.86535 


77.80 


70.97 


61.41 


0.85846 


80 30 


73.83 


63.38 


0.87190 


75 35 


68.22 


59.48 


0.86521 


77 85 


71.03 


61.45 


0.85832 


80 35 


73.89 


63.42 


0.87177 


75.40 


68.27 


59.52 


0.86508 


77.90 


71.08 


61.49 


0.85818 


80.40 


73.95 


63.46 


0.87164 


75.45 


68.33 


59.56 


0.86494 


77.95 


71.14 


61.53 


0.85804 


80.45 


74.01 


63.50 


0.87151 


75.50 


68.38 


59.60 


0.86480 


78.00 


71.19 


61.57 


0.85789 


80.50 


7 4. 06 


63.54 


0.87138 


75 55 


68.44 


59.64 


0.86466 


78.05 


71.25 


61.61 


0.85775 


80.55 


74.12 


63.58 


0.87125 


75.60 


68.49 


59.67 


0.86453 


78 10 


71.31 


61.65 


0.85761 


80.60 


74. 18 


63.62 


0.87111 


75.65 


68.55 


59.71 


0.86439 


78.15 


71.37 


61.69 


0.85747 


80.65 


74.24 


63.66 


0.87098 


75.70 


68.60 


59.75 


0.86426 


78 20 


71.42 


61.73 


0.85733 


80.70 


74.30 


63.70 


0.87084 


75.75 


68.66 


59.79 


0.86412 


78 25 


71.48 


61.77 


0.85719 


80.75 


74.36 


63.74 


0.87071 


75.80 


68.72 


59.83 


0.86399 


78 30 


71.54 


61.81 


0.85705 


80 80 


74.42 


63.78 


0.87058 


75 85 


68.78 


59.87 


0.86385 


78 35 


71.60 


61.85 


0.85691 


80 85 


74-48 


63.82 


0.87045 


75.90 


68.83 


59.91 


0.86371 


78.40 


71.65 


61.88 


0.85677 


80 90 


74.53 


63.86 


0.87032 


75.95 


68.89 


59.95 


0.86357 


78.45 


71.71 


61.92 


0.85663 


80.95 


74.59 


63.90 


0.87019 


76 00 


6R.94 


59.99 


0.86344 


78 50 


71.76 


61.96 


0.85648 


81 00 


74.65 


63.94 


0.87005 


76.05 


69.00 


60.03 


0.86330 


78 55 


71.82 


62.00 


0.85634 


81.05 


74.71 


63.98 


0.86992 


76 10 


69.05 


60.07 


0.86316 


78 60 


71.88 


62.04 


0.85620 


81.10 


74.77 


64.02 


0.86979 


76.15 


69.11 


60.11 


0.86302 


78 65 


71.94 


62.08 


0.85606 


81.15 


74.83 


64.06 


0,86966 


76 20 


69.16 


60.15 


0.86289 


78.70 


71.99 


62.12 


0.85592 


81.20 


74-88 


64.09 


0.86952 


76.25 


69.2i 


60.19 


0.86275 


78.75 


72.05 


62.16 


0.85578 


81.25 


74.94 


64.13 


0.86939 


76.30 


69.27 


60.23 


0.86261 


78.80 


72.11 


62.20 


0.85564 


81 30 


75.00 


64.17 


0.86925 


76 35 


69.33 


60.27 


0.86247 


78 85 


72.17 


62.24 


0.85550 


81.35 


75.06 


64.21 


0.86912 


76.40 


69. Si 


60.31 


0.86234 


78 90 


72.22 


62.28 


0.85536 


81.40 


75.12 


64.25 


0.86898 


76.45 


69.46 


60.35 


0.86220 


78.95 


72.28 


62.32 


0.85522 


81.45 


75.18 


64.29 


0.86885 


76 50 


69.56 


60.39 


0.86206 


79 00 


72.34 


62.36 


0.85507 


81 50 


75.24 


64.33 


0.86872 


76 55 


69.56 


60.43 


0.86192 


79 05 


72.40 


62,40 


0.85493 


81.55 


75.30 


64.37 


0.86859 


76 60 


69.61 


60.47 


0.86179 


79.10 


72.45 


62.44 


0.85478 


81.60 


75.35 


64.41 


0.86845 


76 65 


69.67 


60.51 


0.86165 


79 15 


72.51 


62.48 


0.85464 


81 65 


75.41 


64.45 


0.86832 


76.70 


69.72 


60.54 


0.86151 


79.20 


72.57 


62.52 


0.85450 


81.70 


75.47 


64.49 



XVI] 



WINES 



205 



Table 16. — Alcohol Table.— Continued. 



SPECIFIC 


ALCOHOL 


SPECIFIC 


ALCOHOL 


SPECIFIC 


ALCOHOL 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


20° C. 


Per cent 


1 Per 


Grams 


GRAVITY 

20° c. 


Per cent 


Per 


Grams 


4° 


by volume 


cent by 


per 


4° 


by volume|cent by 


per 


4° 


by volume cent by 


per 




at 20° C. 


weight 


100 cc. 




at 20° C. 


' weight 


100 cc. 




at 20° 0. 


weight 


100 cc. 


0.85436 


81 75 


75.53 


64.53 


0.84713 


84.25 


78.50 


66.50 


0.83957 


86.75 


81.56 


68.48 


0.85422 


81 80 


75.59 


64.57 


0.84698 


84.30 


78.56 


66.54 


0.83942 


86.80 


81.62 


68.52 


0.85408 


81.85 


75.65 


64.61 


0.84683 


84 35 


78.62 


66.58 


0.83927 


86.85 


81.68 


68.56 


0.85393 


81 90 


75.71 


64.65 


0.84668 


84.40 


78.68 


66.62 


0.83912 


86.90 


81.75 


68.60 


0.85379 


81.95 


75.77 


64.69 


0.84654 


84.45 


78.74 


66.66 


0.83896 


86.95 


81.81 


68.64 


0.85364 


82.00 


75.82 


64.73 


0.84639 


84.50 


78.80 


66.70 


0.83881 


87.00 


81.87 


68.68 


0.85350 


82 05 


75.88 


64.77 


0.84624 


84.56 


78.86 


66.74 


0.83865 


87.05 


81.93 


68.72 


0.85336 


82 10 


75.94 


64.81 


0.84609 


84.60 


78.93 


66.78 


0.83850 


87.10 


81.99 


68.76 


0.85322 


82.15 


76.00 


64.85 


0.84594 


84.65 


78.99 


66.82 


0.83834 


87.15 


82.05 


68.80 


0.85307 


82,20 


76.06 


64.88 


0.84579 


84.70 


79.05 


66.86 


0.83818 


87.20 


82.12 


68.84 


0.85293 


82.25 


76.12 


64.92 


0.84564 


84.75 


79.11 


66.90 


0.83802 


87.25 


82.18 


68.88 


0.85279 


82.30 


76.18 


64.96 


0.84549 


84.80 


79.17 


66.94 


0.83787 


87.30 


82.24 


68.91 


0.85265 


82.35 


76.24 


65.00 


0.84534 


84.85 


79.23 


66.98 


0.83771 


87.35 


82.30 


68.95 


0.85250 


82.40 


76.30 


65.04 


0.84519 


84.90 


79.29 


67.02 


0.83756 


87.40 


82.37 


68.99 


0.85236 


82.45 


76.36 


65.08 


0.84504 


84.95 


79.35 


67.06 


0.83740 


87.45 


82.43 


69.03 


0.85222 


82.50 


76.41 


65.12 


0.84489 


85.00 


79.41 


67.09 


0.83725 


87.50 


82.49 


69.07 


0.85207 


82.55 


76.47 


65.16 


0.84474 


85 05 


79.47 


67.13 


0.83709 


87.66 


82.55 


69.11 


0.85192 


82.60 


76.53 


65.20 


0.84459 


85 10 


79.53 


67.17 


0.83694 


87.60 


82.62 


69.15 


0.85178 


82.65 


76.59 


65.24 


0.84444 


85 15 


79.59 


67.21 


0.83678 


87.65 


82.68 


69.19 


0.85164 


82.70 


76.65 


65.28 


0.84429 


85.20 


79.65 


67.25 


0.83663 


87.70 


82.74 


69.23 


0.85150 


82 75 


76.71 


65.32 


0.84414 


85.25 


79.71 


67.29 


0.83647 


87.75 


82.80 


69.27 


0.85135 


82.80 


76.77 


65.36 


0.84399 


85 30 


79.78 


67.33 


0.83632 


87.80 


82.87 


69.30 


0.85121 


82 85 


76.83 


65.40 


0.84384 


85 35 


79.84 


67.37 


0.83616 


87.85 


82.93 


69.34 


0.85106 


82 90 


76.89 


65.44 


0.84369 


85.40 


79.90 


67.41 


0.83601 


87.90 


82.99 


69.38 


0.85092 


82.95 


76.95 


65.48 


0.84354 


85.45 


79.96 


67.45 


0.83585 


87.95 


83.05 


69.42 


0.85077 


83 00 


77.01 


65.51 


0.S4339 


85.50 


80.02 


67.49 


0.83569 


88.00 


83.12 


69.46 


0.85063 


83 05 


77.07 


65.55 


0.84323 


85 55 


80.08 


67.53 


0.83553 


88.05 


83.18 


69.50 


0.85049 


83.10 


77.13 


65.59 


0.84308 


85.60 


80.14 


67.57 


0.83537 


88.10 


83.25 


69.54 


0.85035 


83.15 


77.19 


65.63 


0.84293 


85 65 


80.20 


67.61 


0.83521 


88.15 


83.31 


69.58 


0.85020 


83.20 


77.24 


65.67 


0.84278 


85.70 


80.27 


67.65 


0.83505 


88.20 


83.37 


69.62 


0.85006 


83 25 


77.30 


65.71 


0.84263 


85 75 


80.33 


67.69 


0.83489 


88.26 


83.43 


69.66 


0.84991 


83 30 


77.36 


65.75 


0.84248 


85 80 


80.39 


67.73 


0.83473 


88.30 


83.50 


69.70 


0.84977 


83 35 


77.42 


65.79 


0.84233 


85.85 


80. 45 


67.77 


0.83457 


88.35 


83.56 


69.74 


0.84962 


83 40 


77.48 


65.83 


0.84218 


86.90 


80.51 


67.80 


0.83442 


88.40 


83.63 


69.78 


0.84948 


83.45 


77.54 


65.87 


0.84203 


85.96 


80.57 


67.84 


0.83426 


88.45 


83.69 


69.82 


0.84933 


83.50 


77.60 


65.91 


0.84188 


86.00 


80.63 


67.88 


0.83410 


88.50 


83.75 


69.86 


0.84918 


83 55 


77.66 


65.95 


0.84172 


86 05 


80.69 


67.92 


0.83394 


88.55 


83.81 


69.90 


0.84903 


83 60 


77.72 


65.99 


0.84157 


86.10 


80.76 


67.96 


0.83379 


88.60 


83.88 


69.94 


0.84889 


83 65 


77.78 


66.03 


0.84141 


86.16 


80.82 


68.00 


0.83363 


88.66 


83.94 


69.98 


0.84874 


83 70 


77.84 


66.07 


0.84126 


86.20 


80.88 


68.04 


0.83347 


88.70 


84.00 


70.01 


0.84859 


83 75 


77.90 


66.11 


0.84110 


86.26 


80.94 


68.08 


0.83331 


88.75 


84.06 


70.05 


0.84844 


83 80 


77.96 


66.15 


0.84095 


86 30 


81.00 


68.12 


0.83315 


88.80 


84.13 


70.09 


0.84830 


83 85 


78.02 


66.19 


0.84080 


86.36 


81.06 


68.16 


0.83299 


88.85 


84.19 


70.13 


0.84815 


83.90 


78.08 


66.23 


0.84065 


86.40 


81.13 


68.20 


0.83283 


88.90 


84.26 


70.17 


0.84801 


83.95 


78.14 


66.27 


0.84049 


86.45 


81.19 


68.24 


0.83267 


88.95 


84.32 


70.21 


0.84786 


84.00 


78.20 


66.30 


0.84034 


86.60 


81.25 


68.28 


0.83251 


89.00 


84.39 


70.25 


0.84772 


84.05 


78.26 


66.34 


0.84018 


86.55 


81.31 


68.32 


0.83235 


89.06 


84.45 


70.29 


0.84757 


84 10 


78.32 


66.38 


0.84003 


86.60 


81.37 


68.36 


0.83219 


89.10 


84.51 


70.33 


0.84742 


84,15 


78.38 


66.42 


0.83987 


86.65 


81. 43 


68.40 


0.83203 


89.16 


84.57 


70.37 


0.84727 


84 20 


78.44 


66.46 


0.83972 


86.70 


81.50 


68.44 


0.83186 


89.20 


84.64 


70.41 



206 



METHODS OF ANALYSIS 



[Chap. 



5 






Tabl 


E 16.— Alcohol Table.- 


—Continued. 










ALCOHOL 






ALCOHOL 








ALCOHOL 




SPECIFIC 








SPECIFIC 








SPECIFIC 








QKAVITY 

20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


1 Per 


Grams 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 


4° 


by volumelcent by 


per 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.83170 


89 25 


8^.70 


70.45 


0.82332 


91 75 


87.96 


72.42 


0.81432 


94.25 


91.36 


74.40 


0.83154 


89 30 


84.77 


70.49 


0.82315 


91 80 


88.03 


72.46 


0.81413 


94 30 


91.43 


74.44 


0.83138 


89 36 


84.83 


70.53 


0.82298 


91 85 


88.09 


72.50 


0.81394 


94 35 


91.50 


74.48 


0.83121 


89 40 


84.90 


70.57 


0.82281 


91.90 


88.16 


72.54 


0.81375 


94 40 


91.57 


74.52 


0.83105 


89.45 


84.96 


70.61 


0.82263 


91.95 


88.22 


72.58 


0.81356 


94 45 


91.64 


74.56 


0.83089 


89 50 


85.03 


70.65 


0.82246 


92.00 


88.29 


72.62 


0.81337 


94 50 


91.71 


74.59 


0.83073 


89 55 


85.09 


70.69 


0.82229 


92 05 


88.36 


72.66 


0.81318 


94 55 


91.78 


74.63 


0.83056 


89 60 


85.15 


70.72 


0.82212 


92 10 


88.43 


72.70 


0.81299 


94.60 


91.85 


74.67 


0.83040 


89 65 


85.21 


70.76 


0.82194 


92.15 


88.49 


72,74 


0.81280 


94.65 


91.92 


74.71 


0.83024 


89.70 


85.28 


70.80 


0.82177 


92 20 


88.56 


72,78 


0.81260 


94.70 


91.99 


74.75 


0.83008 


89 75 


85.34 


70.84 


0.82159 


92 25 


88.63 


72,82 


0.81241 


94 75 


92.06 


74.79 


0.82991 


89.80 


85.41 


70.88 


0.82141 


92 30 


88.70 


72,86 


0.81222 


94 80 


92.13 


74.83 


0.82975 


89 85 


85.47 


70.92 


0.82123 


92 35 


88.76 


72,90 


0.81202 


94 85 


92.20 


74.87 


0.82958 


89 90 


85.54 


70.96 


0.82106 


92 40 


88.83 


72,94 


0.81183 


94 90 


92.27 


74.91 


0.82942 


89 95 


85.60 


71.00 


0.82088 


92 45 


88.89 


72.98 


0.81163 


94 95 


92.34 


74.95 


0.82925 


90 00 


85.67 


71.04 


0.82071 


92 50 


88.96 


73.02 


0.81144 


95 00 


92.41 


74.99 


0.82909 


90 05 


85.73 


71.08 


0.82053 


92 55 


89.03 


73.06 


0,81124 


95 05 


92.48 


75.03 


0.82892 


90.10 


85.80 


71.12 


0.82035 


92 60 


89.10 


73.09 


0.81105 


95 10 


92.55 


75.07 


0.82876 


90 15 


85.86 


71.16 


0.82017 


92 65 


89.16 


73.13 


0.81086 


95.15 


92.63 


75.11 


0.82859 


90 20 


85.93 


71.20 


0.82000 


92.70 


89.23 


73.17 


0.81067 


95.20 


92.70 


75.15 


0.82843 


90 25 


85.99 


71.24 


0.81982 


92.75 


89.30 


73.21 


0.81047 


95 25 


92.77 


75.19 


0.82826 


90 30 


86.06 


71.28 


0.81964 


92 80 


89.37 


73.25 


0.81028 


95.30 


92.84 


75.23 


0.82810 


90 35 


86.12 


71.32 


0.81946 


92 85 


89.43 


73.29 


0.81008 


95 35 


92.91 


75.27 


0.82793 


90 40 


86.19 


71.36 


0.81929 


92 90 


89.50 


73.33 


0.80988 


95 40 


92.98 


75.30 


0.82776 


90 45 


86.25 


71.40 


0.81911 


92 95 


89.57 


73.37 


0.80968 


95 45 


93.05 


75.34 


0.82759 


90 50 


86.32 


71.44 


0.81893 


93 00 


89.64 


73,41 


0.80949 


95 50 


93.12 


75.38 


0.82742 


90 55 


86.38 


71.48 


0.81875 


93 05 


89.71 


73.45 


0,80929 


95 55 


93.20 


75.42 


0.82725 


90 60 


86.45 


71.52 


0.81856 


93 10 


89.78 


73,49 


0.80909 


95.60 


93.27 


75.46 


0.82708 


90 65 


86.51 


71.56 


0.81838 


93.15 


89.84 


73,53 


0.80889 


96 65 


93.34 


75.50 


0.82691 


90 70 


86.58 


71.59 


0.81821 


93 20 


89.91 


73.57 


0.80869 


95.70 


93.41 


75.54 


0.82674 


90 75 


86.64 


71.63 


0.81803 


93 25 


89.98 


73.61 


0.80849 


95 75 


93.48 


75.58 


0.82657 


90 80 


86.71 


71.67 


0.81784 


93 30 


90.05 


73.65 


0,80829 


95 80 


93.55 


75.62 


0.82640 


90 85 


86.77 


71.71 


0.81766 


93 35 


90.12 


73.69 


0.80809 


96 86 


93.63 


75.66 


0.82624 


90 90 


86.84 


71.75 


0.81748 


93 40 


90.19 


73.72 


0.80789 


95 90 


93.70 


75.70 


0.82607 


90 95 


86.90 


71.79 


0.81730 


93 45 


90.25 


73.76 


0.80769 


95.95 


93.77 


75.74 


0.82590 


91 00 


86.97 


71.83 


0.81711 


93 50 


90.32 


73.80 


0,80749 


96 00 


93.84 


75.78 


0.82573 


91 05 


87.03 


71.87 


0.81693 


93 55 


90.39 


73,84 


0,80729 


96 06 


93.92 


75.82 


0.82556 


91 10 


87.10 


71.91 


0.81675 


93 60 


90.46 


73,88 


0.80709 


96.10 


93.99 


75.86 


0.82539 


91.15 


87.17 


71.95 


0.81657 


93 65 


90.53 


73.92 


0.80689 


96,16 


94.06 


75.90 


0.82522 


91 20 


87.24 


71.99 


0.81638 


93 70 


90.60 


73.96 


0.80668 


96,20 


94.13 


75.94 


0.82505 


91 25 


87.30 


72.03 


0.81620 


93 75 


90.67 


74,00 


0.80648 


96 26 


94.21 


75.98 


0.82488 


91 30 


87.37 


72.07 


0.81601 


93 80 


90.74 


74.04 


0.80627 


96 30 


94.28 


76.01 


0.82470 


91.35 


87.43 


72.11 


0.81582 


93 85 


90.80 


74.08 


0.80607 


96 36 


94.35 


76.05 


0.82453 


91 40 


87.50 


72.15 


0.81563 


93 90 


90.87 


74.12 


0.80586 


96.40 


94.42 


76.09 


0.82436 


91 45 


87.56 


72.19 


0.81545 


93 95 


90.94 


74.16 


0.80566 


96.45 


94.50 


76.13 


0.82419 


91 50 


87.63 


72.23 


0.81526 


94,00 


91.01 


74.20 


0.80545 


96 60 


94.57 


76.17 


0.82401 


91 55 


87.69 


72.27 


0.81507 


94 05 


91.08 


74.24 


0.80525 


96 56 


94.65 


76.21 


0.82384 


91 60 


87.76 


72.30 


0.81488 


94 10 


91.15 


74.28 


0.80504 


96 60 


94.72 


76.25 


0.82367 


91 65 


87.83 


72.34 


0.81469 


94 15 


91.22 


74.32 


0.80483 


96 65 


94.79 


76.29 


0.82350 


91.70 


87.90 


72.38 


0.81450 


94.20 


91.29 


74,30 


0.80462 


96.70 


94.86 


76.33 



XVI] 



WINES 



207 



5 






Table 16.— Alcohol Table.- 


—Concluded. 








SPECIFIC 


ALCOHOL 


SPECIFIC 
GR WITY 


ALCOHOL 


SPECIFIC 


ALCOHOL 


20° C. 


Per cent 


Per 


Grams 


20° C. 


Per cent 


Per 


Grams 


GRAVITY 

20° C. 


Per cent 


Per 


Grama 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 


4° 


by volume 


cent by 


per 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 




at 20° C. 


weight 


100 cc. 


0.80442 


96.75 


94.94- 


76.37 


0.79900 


98.00 


96.82 


77.36 


0.79311 


99 25 


98.78 


78.34 


0.80421 


96.80 


95.01 


76.41 


0.79878 


98 05 


96.90 


77.40 


0.79286 


99 30 


98.86 


78.38 


0.80400 


96 85 


95.09 


76.45 


0.79855 


98 10 


96.97 


77.43 


0.79262 


99 35 


98.94 


78.42 


0.80379 


96 90 


95.16 


76.49 


0.79832 


98.15 


97.05 


77.47 


0.79237 


99 40 


99.02 


78.46 


0.80358 


96 95 


95.24 


76.53 


0.79809 


98 20 


97.12 


77.51 


0.79213 


99.45 


99.10 


78.50 


0.80337 


97.00 


95.31 


76.57 


0.79786 


98.25 


97.20 


77.55 


0.79188 


99 50 


99.18 


78.54 


0.80315 


97.05 


95.39 


76.61 


0.79763 


98.30 


97.28 


77.59 


0.79163 


99.55 


99.26 


78.58 


0.80294 


97.10 


95.46 


76.65 


0.79740 


98.35 


97.36 


77.63 


0.79138 


99 60 


99.34 


78.62 


0.80273 


97.15 


95.53 


76.69 


0.79717 


98.40 


97.43 


77.67 


0.79113 


99.65 


99.42 


78.66 


0.80252 


97.20 


95.60 


76.72 


0.79695 


98.45 


97.51 


77.71 


0.79088 


99.70 


99.51 


78.70 


0.80230 


97.25 


95.68 


76.76 


0.79672 


98 50 


97.59 


77.75 


0.79062 


99 75 


99.59 


78.74 


0.80208 


97 30 


95.75 


76.80 


0.79648 


98 55 


97.67 


77.79 


0.79037 


99 80 


99.67 


78.78 


0.80186 


97 35 


95.83 


76.84 


0.79625 


98.60 


97.75 


77.83 


0.79011 


99 85 


99.75 


78.82 


0.80164 


97.40 


95.91 


76.88 


0.79601 


98 65 


97.83 


77.87 


0.78986 


99.90 


99.83 


78.86 


0.80143 


97.45 


95.98 


76.92 


0.79577 


98 70 


97.90 


77.91 


0.78960 


99 95 


99.91 


78.90 


0.80122 


97 50 


96.05 


76.96 


0.79553 


98 75 


97.98 


77.95 


0.78934 


100.00 


100.00 


78.93 


0.80100 


97.55 


96.13 


77.00 


0.79529 


98.80 


98.06 


77.99 










0.80078 


97 60 


96.21 


77.04 


0.79505 


98 85 


98.14 


78.03 










0.80056 


97.65 


96.29 


77.08 


0.79481 


98 90 


98.22 


78.07 










0.80034 


97.70 


96.36 


77.12 


0.79457 


98 95 


98.30 


78.11 










0.80012 


97.75 


96.44 


77.16 


0.79432 


99.00 


98.38 


78.14 










0.79990 


97 80 


96.52 


77.20 


0.79408 


99.05 


98.46 


78.18 










0.79968 


97 85 


96.60 


77.24 


0.79384 


99.10 


98.54 


78.22 










0.79945 


97.90 


96.68 


77.28 


0.79360 


99 15 


98.62 


78.26 










0.79923 


97 95 


96.75 


77.32 


0.79335 


99 20 


98.70 


78.30 











208 



METHODS OF ANALYSIS 



[Chap, 



Table 17.— Alcohol 
For calculating the percentages of alcohol in mixtures of ethyl alcohol and 





17.5 


'C. 


18° 


C. 


19 


c. 


20° 


C. 


21° C. 


SCALE 




















READINQ 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


13.2 




















13.3 




















13.4 




















13.5 




















13.6 




















13.7 




















13.8 




















13.9 




















14.0 




















14.1 




















14.2 


















6 04 


14.3 


















13 


14.4 


















21 


14.5 














0.08 


0.06 


29 


14.6 














16 


0.13 


38 


14.7 










05 


0.04 


25 


0.20 


0.46 


14.8 










0,14 


0.11 


0.34 


0.27 


0,56 


14.9 






001 


0.01 


0,23 


0.18 


0,43 


0.34 


0,64 


15.0 


0.00 


0.00 


0.10 


0.08 


0,31 


0.24 


0,62 


0.41 


0.73 


15.1 


0,09 


0.07 


0.19 


0.15 


39 


0.31 


60 


0.48 


82 


15.2 


17 


0.13 


27 


0.21 


0,48 


0.38 


69 


0.55 


0.91 


15.3 


26 


0.20 


0.35 


0.28 


0,57 


0.45 


0,77 


0.61 


0.99 


15.4 


0.34 


0.27 


0.44 


0.35 


0,65 


0.51 


0.85 


0.68 


1.07 


15.5 


0.43 


0.S4 


0.53 


0.42 


0,73 


0.58 


0.94 


0.75 


1.16 


15.6 


0.51 


0.40 


0.60 


0.48 


0,82 


0.65 


1.03 


0.82 


1.24 


15.7 


0.69 


0.47 


69 


0.55 


91 


0.72 


1.12 


0.89 


1.32 


15.8 


68 


0.54 


0.78 


0.62 


99 


0.79 


1.21 


0.96 


1.40 


15.9 


0.76 


0.60 


0.85 


0.68 


1,08 


0.86 


1.28 


1.02 


1.47 


16.0 


0.84 


0.67 


0.94 


0.75 


1.17 


0.93 


1.36 


1.08 


1.55 


16.1 


0.93 


0.74 


1.03 


0.82 


1.24 


0.99 


1.44 


1.14 


1.62 


16.2 


1.02 


0.81 


1,12 


0.89 


1.32 


1.05 


1,51 


1.20 


1.70 


16.3 


1.10 


0.87 


1,19 


0.95 


1.40 


1.11 


1,59 


1.26 


1.77 


16.4 


1.18 


0.94 


1,29 


1.02 


1.47 


1.17 


1,66 


1.32 


1.86 


16.5 


1.26 


1.00 


1,36 


1.08 


1,55 


1.23 


1,74 


1.38 


1.92 


16.6 


1.34 


1.06 


1,43 


1.13 


1 62 


1.29 


1,81 


1.44 


2.00 


16.7 


1.41 


1.12 


1,50 


1.19 


1 70 


1.35 


1,89 


1.50 


2.07 


16.8 


1.49 


1.18 


1,57 


1.25 


1.77 


1.41 


1,96 


1.66 


2.16 


16.9 


1.56 


1.24 


1,65 


1.31 


1,85 


1.47 


2,04 


1.62 


2.22 


17.0 


1.63 


1.30 


1,72 


1.37 


1,92 


1.53 


2.11 


1.68 


2.30 


17.1 


1.70 


1.35 


1.80 


1.43 


1,99 


1.58 


2.19 


1.74 


2.37 


17.2 


1.77 


1.41 


1.87 


1.49 


2 06 


1.64 


2.26 


1.80 


2.45 


17.3 


1.85 


1.47 


1,94 


1.54 


2,14 


1.70 


2.34 


1.86 


2.62 


17.4 


1.92 


1.53 


2.01 


1.60 


2,21 


1.76 


2.41 


1.92 


2.59 


17.5 


2.00 


1.59 


2.09 


1.66 


2.29 


1.82 


2.49 


1.98 


2.66 


17.6 


2.07 


1.65 


2.16 


1.72 


2.36 


1.88 


2.56 


2.04 


2.74 


17.7 


2.14 


1.70 


2.24 


1.78 


2,44 


1.94 


2,62 


2.09 


2,81 


17.8 


2.21 


1.76 


2 31 


1.84 


2.51 


2.00 


2,70 


2.15 


2,89 


17.9 


2.29 


1.82 


2.38 


1.89 


2.69 


2.06 


2,77 


2.21 


2,96 



' Calculated and arranged by B. H. St. John from the data of Doroshevskii and Dvorzhanchik.' 



XVI] 



WINES 



Table. 

water from their Zeias immersion refractometer readings* at 17.5°-25°C. 



209 
6 



21°C. 


22° 


c. 


23 


'C. 


24 


c. 


25° 


c. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


PCALB 
READING 


by 


by 


by 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


















0.00 


0.00 


13.2 
















09 


0.07 


13.3 
















0.18 


0.14 


13.4 












05 


0.04 


0.26 


0.21 


13.5 












0.14 


0.11 


35 


0.28 


13.6 








o.oi 


0.01 


23 


0.18 


0.44 


0.85 


13.7 








0.10 


0.08 


0.31 


0.25 


53 


0.42 


13.8 








0.19 


0.15 


0.40 


0.32 


0.62 


0.49 


13.9 




0.08 


0.06 


0.28 


0.22 


0.49 


0.39 


70 


0.56 


14.0 




0.16 


0.13 


0.36 


0.29 


0.58 


0.46 


0.79 


0.63 


14.1 


o'.os 


0.24 


0.19 


45 


0.36 


67 


0.53 


88 


0.70 


14.2 


0.10 


33 


0.26 


0.54 


0.43 


0.75 


0.60 


0.97 


0.77 


14.3 


0.17 


0.41 


0.33 


0.63 


0.50 


0.84 


0.67 


1.06 


0.85 


14.4 


0.23 


0.50 


0.40 


0.72 


0.57 


93 


0.74 


1.15 


0.92 


14.5 


O.SO 


0.59 


0.47 


0.80 


0.64 


1.02 


0.81 


1.24 


0.99 


14.6 


0.S7 


0.68 


0.54 


0.89 


0.71 


1 11 


0.88 


1 32 


1.05 


14.7 


o.U 


0.77 


0.61 


0.98 


0.78 


1.19 


0.95 


1.40 


1.11 


14.8 


0.51 


0.85 


0.68 


1.07 


0.85 


1.28 


1.02 


1.47 


1.17 


14.9 


0.58 


0.94 


0.75 


1.16 


0.92 


1.36 


1.08 


1 55 


1.23 


15.0 


0.65 


1.03 


0.82 


1.24 


0.99 


1.44 


1.14 


1.63 


1.29 


15.1 


0.72 


1.13 


0.89 


1.32 


1.05 


1.51 


1.20 


1.71 


1.36 


15.2 


0.79 


1.21 


0.96 


1.40 


1.11 


1.59 


1.26 


1.79 


1.42 


15.3 


0.85 


1.29 


1.02 


1.47 


1.17 


1.66 


1.32 


1.86 


1.48 


15.4 


0.92 


1.36 


1.08 


1.55 


1.28 


1.74 


1.88 


1.94 


1.54 


15.5 


0.99 


1.44 


1.15 


1.62 


1.29 


1.82 


1.44 


2.01 


1.60 


15.6 


1.05 


1 52 


1.21 


1.70 


1.35 


1.90 


1.51 


2.09 


1.66 


15.7 


1.11 


1.60 


1.27 


1.77 


1.41 


1.97 


1.57 


2.17 


1.72 


15.8 


1.17 


1.67 


1.33 


1.85 


1.47 


2.05 


1.63 


2 25 


1.79 


15.9 


1.23 


1.75 


1.39 


1.92 


1.53 


2.12 


1.69 


2.33 


1.85 


16.0 


1.29 


1.82 


1.45 


2.00 


1.59 


2.20 


1.75 


2.40 


1.91 


16.1 


1.85 


1 90 


1.51 


2.08 


1.65 


2.27 


1.81 


2.48 


1.97 


16.2 


HI 


1.97 


1.57 


2.16 


1.72 


2.36 


1.87 


2.55 


2.08 


16.3 


1.47 


2.05 


1.63 


2.24 


1.78 


2.43 


1.93 


2.62 


2.09 


16.4 


1.53 


2.12 


1.69 


2.31 


1.84 


2.50 


1.99 


2.70 


2.16 


16.5 


1.59 


2.20 


1.75 


2.39 


1.90 


2.57 


2.05 


2.77 


2.21 


16.6 


1.65 


2.27 


1.81 


2 46 


1.96 


2.65 


2.11 


2.85 


2.27 


16.7 


1.71 


2.35 


1.87 


2.53 


2.02 


2.72 


2.17 


2.92 


2.38 


16.8 


1.77 


2.43 


1.93 


2.61 


2.08 


2.80 


2.23 


2.99 


2.88 


16.9 


1.83 


2.50 


1.99 


2.69 


2.14 


2.87 


2.29 


3.06 


2-44 


17.0 


1.89 


2.57 


2.05 


2.76 


2.20 


2.95 


2.35 


3.14 


2.50 


17.1 


1.95 


2.65 


2.11 


2.82 


2.25 


3.02 


2.41 


3.21 


2.56 


17.2 


2.01 


2.72 


2.17 


2.90 


2.31 


3.10 


2.47 


3.29 


2.62 


17.3 


2.07 


2.79 


2.23 


2.97 


2.37 


3.17 


2.58 


3.36 


2.68 


17.4 


2.12 


2.86 


2.28 


3.04 


2.43 


3.25 


2.59 


3 43 


2.74 


17.5 


2.18 


2.94 


2.34 


3.12 


2.49 


3.32 


2.65 


3.51 


2.80 


17.6 


2.24 


3.01 


2.40 


3.20 


2.55 


3 39 


2.70 


3 58 


2.86 


17.7 


2.30 


3.09 


2.46 


3.27 


2.61 


3.46 


2.76 


3.66 


2.92 


17.8 


2.36 


3.16 


2.52 


3.35 


2.67 


3.53 


2.82 


3.73 


2.98 


17.9 



210 






METHODS OF 


AJ^ALYSIS 




[Chap. 


6 














Table 17.- 


-Alcohoi 




17.5 


"C. 


18° 


c. 


19° 


C. 


20° 


C. 


arc. 


RUAUINQ 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volunio 


weight 


volume 


weight 


volume 


weight 


volume 


18,0 


2 36 


L88 


2 45 


1.95 


2 66 


2.12 


2 85 


2.27 


3 04 


18.1 


2 43 


l.H 


2 52 


2.01 


2 74 


2.18 


2 92 


2.33 


3.11 


18.2 


2 50 


2.00 


2.60 


2.07 


2 81 


2 .24 


3 00 


2.39 


3 19 


18.3 


2 57 


2.05 


2.67 


2.13 


2 89 


2. SO 


3 07 


2.45 


3 26 


18.4 


2 66 


2. It 


2 75 


2.19 


2 96 


2.36 


3 15 


2.61 


3 34 


18.5 


2 72 


2.17 


2 82 


2.25 


3 03 


2.41 


3 22 


2.57 


3 41 


IS.O 


2 80 


2.23 


2 90 


2.31 


3 10 


2.47 


3 30 


2.63 


3 48 


18.7 


2 87 


2.29 


2 97 


2.37 


3 17 


2 . 53 


3 37 


2.69 


3 56 


18,8 


2 95 


2.S5 


3 05 


2.43 


3 25 


2.59 


3 45 


2.75 


3 63 


18.9 


3 02 


2.41 


3 12 


2.49 


3 32 


2.65 


3 52 


2.81 


3 70 


19.0 


3 10 


2.47 


3 19 


2.54 


3 40 


2.71 


3 59 


2.86 


3 77 


19.1 


3 17 


2.53 


3 26 


2.60 


3 47 


2.77 


3.66 


2 .92 


3 85 


10.2 


3 25 


2.69 


3 34 


2.66 


3 55 


2.83 


3 73 


2.98 


3 92 


19. ;{ 


3 32 


2.65 


3 41 


2.72 


3 62 


2 89 


3 81 


3.04 


4 00 


19.4 


3 39 


2.70 


3 48 


2.78 


3 70 


2.95 


3 88 


3.10 


4 07 


19. f) 


3 46 


2.76 


3 56 


2.84 


3 77 


3.01 


3 96 


3.16 


4.14 


10.0 


3 53 


2.82 


3 63 


2.90 


3 84 


3.06 


4 03 


3.22 


4 22 


10 7 


3 61 


2.88 


3 71 


2.96 


3 91 


3.12 


4 10 


3.27 


4.29 


10, S 


3 68 


2.94 


3 78 


3.02 


3 98 


3.18 


4 17 


3. 33 


4.37 


19.9 


3 76 


3.00 


3 86 


3.08 


4 06 


3.24 


4 25 


3.39 


4.44 


20.0 


3 83 


3.06 


3 93 


3.13 


4 13 


3.30 


4 32 


3.45 


4.52 


20.1 


3 90 


3.12 


4 00 


3.19 


4 20 


3.35 


4 39 


3.61 


4 69 


20.2 


3 97 


3.17 


4 07 


3.25 


4 27 


3.41 


4 47 


3.57 


4 66 


20.3 


4 04 


3.23 


4 14 


3. 31 


4 34 


3.47 


4 64 


3.63 


4.74 


20.4 


4 12 


3.29 


4 22 


3.37 


4 42 


3.53 


4 61 


3.68 


4 82 


20.5 


4 19 


3.35 


4 29 


3. 43 


4 49 


3.59 


4.68 


3.74 


4 89 


20.6 


4 26 


3.41 


4 36 


3.49 


4 56 


3.65 


4 75 


3.80 


4 96 


20.7 


4 33 


3.46 


4 43 


3.54 


4 63 


3.70 


4 83 


3.86 


5 03 


20.8 


4 41 


3.52 


4 51 


3.60 


4.70 


3.76 


4 90 


3.92 


5 10 


20.9 


4 48 


3. 58 


4.58 


3.66 


4.78 


3.82 


4.97 


3.98 


5 17 


21.0 


4 56 


S.64 


4 65 


3.72 


4 85 


3.88 


6 04 


4.03 


6 24 


21.1 


4 63 


3 . 70 


4 73 


S . 78 


4 92 


3.94 


5 11 


4.09 


6 31 


21.2 


4 70 


3.76 


4.80 


3.84 


4 99 


3 . 99 


5 19 


4.15 


6 39 


21.3 


4 77 


3.81 


4 87 


3.89 


5 06 


4.05 


5 26 


4.21 


5.46 


21.4 


4 84 


3.87 


4 94 


3.95 


5 14 


4.11 


5 33 


4.26 


5.53 


21.5 


4 92 


3 . 93 


5 01 


4.01 


5 21 


4-17 


5 40 


4.32 


5 60 


21. G 


4 99 


3.99 


5 09 


4.07 


5 28 


4 22 


5 47 


4.38 


5 67 


21.7 


5 06 


4.05 


5 16 


4.13 


5 35 


4 . 28 


6.54 


4-44 


5 75 


21.8 


5 13 


4.10 


5 23 


4.18 


5 43 


4.34 


5 61 


4.49 


6 82 


21.9 


5 20 


4.16 


5 SO 


4.24 


6 50 


4.40 


5 69 


4.56 


5.89 


22.0 


5 27 


4.22 


5 37 


4.30 


5 57 


4.45 


5 76 


4. 61 


5 96 


22 1 


5 34 


4.27 


5.44 


4.35 


5 64 


4.61 


5 83 


4.67 


6 03 


22^2 


5 41 


4. 33 


5 51 


4-41 


6 71 


4.67 


5 90 


4.72 


6 11 


22.3 


5.49 


4.39 


5 68 


4-47 


5 78 


4.63 


5 97 


4.78 


6 18 


22.4 


5.56 


4.45 


5 65 


4.53 


5.85 


4 . 68 


6 05 


4.84 


6.26 


22.5 


5 63 


4.51 


5 72 


4.58 


5 92 


4.74 


6 12 


4.90 


6 32 


22.0 


5 70 


4.66 


5 80 


4.64 


6 00 


4 . so 


6 19 


4.95 


6 39 


22.7 


5 77 


4.62 


5.87 


4.70 


6 07 


4 . 86 


6 26 


5.01 


6 46 


22.8 


5 86 


4.68 


5 94 


4.75 


6 14 


4.91 


6 33 


6.07 


6 63 


22.9 


6 92 


4.74 


6.01 


4.81 


6 21 


4.97 


6.40 


5.13 


6 60 



XVI] 



Table.— Con tinned. 



WINES 



211 
6 



21" C. 


22° 


C. 


23° 


0. 


24° 


C. 


26° 


C. 




Por cont 

by 
weight 


Por cent 

l^y 

volume 


Per cont 

by 
weight 


Por cont 

by 
volume 


Por cont 

by 
weight 


Per (!(>nt 

by 
volunio 


Per cont 

by 
woig;ht 


Por cont 

by 
volume 


Per cont 

by 
weight 


SCAI.K 
RBADINO 


IS. 4^ 


3 23 


2.68 


3 42 


2.73 


3 61 


2 . 88 


3 81 


3.04 


ISO 


S.4S 


3 30 


2.63 


3 60 


2 . 79 


3 68 


2.94 


3 88 


3.10 


IS.l 


2.54 


3 37 


2.69 


3 57 


2.85 


3 76 


3.00 


3 96 


3.16 


IS. -J 


2.60 


3 45 


2.75 


3 64 


2.91 


3 83 


3.06 


4 03 


3 . 22 


IS. 3 


2.66 


3 62 


2.81 


3 71 


2.96 


3 91 


3.12 


4 11 


3 . 28 


IS. 4 


2.72 


3 69 


2.87 


3 78 


3.02 


3 98 


3.18 


4 18 


3.34 


IS.T) 


2.78 


3 66 


2 .92 


3 86 


3.08 


4 06 


3.24 


4 26 


3.40 


IS. 6 


2.83 


3 73 


2.98 


3 93 


3.14 


4 13 


3 . 30 


4 33 


3 . 46 


IS. 7 


2.89 


3 81 


3. 04 


4 01 


3 . 20 


4 21 


3 . 36 


4 41 


3.52 


IS S 


2.95 


3 88 


3. to 


4 08 


3.26 


4 28 


3.42 


4 48 


3.58 


1S.<) 


S.Oi 


3 96 


3.16 


4 16 


3 32 


4 36 


3 . 48 


4 56 


3.64 


l!M) 


S.07 


4 03 


3.22 


4 23 


3.38 


4 43 


3.54 


4 63 


3.70 


!'.► I 


S.IS 


4 11 


3.28 


4.31 


S.44 


4 51 


3.60 


4 70 


3.76 


19.2 


S.19 


4 18 


3. 34 


4 38 


3.50 


4 58 


3 . 66 


4 78 


3.82 


10.3 


S.25 


4.26 


3.40 


4 46 


3.56 


4 65 


3 7 '3 


4 85 


3.88 


10.4 


S.St 


4 33 


3.46 


4 53 


3.6:3 


4 73 


3 . 78 


4 93 


3.94 


10. f) 


S.S7 


4 41 


3.52 


4 61 


3 . 68 


4 80 


3.84 


5 00 


4.00 


10.0 


S.4S 


4 48 


3.58 


4.68 


3.74 


4 88 


3.90 


5 08 


4. 06 


10.7 


3.49 


4 66 


3.64 


4 75 


3 . 80 


4 96 


3.96 


6 16 


4.12 


10.8 


S.55 


4 63 


3.70 


4 83 


3 . 86 


5 03 


4.02 


6 22 


4.17 


10.9 


S.6I 


4 72 


3.77 


4 90 


3 . 92 


5 10 


4.08 


6 29 


4.23 


•20 


8.67 


4 79 


3 . 83 


4 98 


3 . 98 


5 17 


4.13 


6 36 


4 . 29 


20,1 


S.7S 


4 87 


3.89 


5 05 


4.04 


6 24 


4.19 


6 44 


4.35 


20 2 


3 . 79 


4 94 


3.95 


6 13 


4.10 


5 31 


4.25 


5 51 


4-41 


20,. S 


S.85 


6 01 


4.01 


5 20 


4. 16 


5 38 


4.31 


5 58 


4-47 


20,1 


3.91 


6 08 


4. 06 


6 27 


4.2t 


6 45 


4.S7 


5 65 


4.52 


20 , f) 


3.97 


6 16 


4.12 


5 34 


4.27 


5 62 


4.42 


5 72 


4.58 


20 , () 


4.02 


6 22 


4.18 


5 41 


4.33 


5 60 


4.4fi 


5 80 


4.64 


20.7 


4.08 


5 29 


4-24 


5.48 


4 . 39 


5 67 


4.54 


5 87 


4.70 


20. S 


4.14 


6 36 


4.29 


5 56 


4.45 


5 75 


4. 60 


5 95 


4.76 


20,0 


4.20 


6 44 


4.35 


5 62 


4.50 


6 82 


4.66 


6 02 


4.81 


21.0 


4.25 


6 61 


4-41 


5 70 


4.56 


5 89 


4.72 


6 09 


4.87 


21.1 


4. St 


6 68 


4-47 


5.77 


4.62 


5 96 


4.77 


6 16 


4.93 


21.2 


4.S7 


5 65 


4.52 


5,84 


4 . 68 


6 03 


4.83 


6 23 


4.99 


21.3 


4.4s 


5.72 


4.58 


5 91 


4.73 


6 11 


4.89 


6 30 


5.05 


21.4 


4-4^ 


6 80 


4-64 


6 98 


4 . 79 


6 18 


4.95 


6 37 


5.10 


21.5 


4.54 


5 87 


4 . 70 


6 06 


4.85 


6 26 


5.01 


6 44 


5.16 


21.0 


4. 60 


5.94 


4.75 


6 13 


4.91 


6 32 


5 . 06 


6.62 


5.22 


21,7 


4.66 


6 01 


4. 81 


6 20 


4.97 


6 39 


5.12 


6 59 


5.28 


21. S 


4.71 


6.08 


4.87 


6 27 


5.02 


6.47 


5.18 


6.66 


5.34 


21.0 


4.77 


6 16 


4 . 93 


6 34 


5.08 


6 54 


5.24 


6.73 


5.39 


22.0 


4.8S 


6 22 


4.98 


6 42 


5.14 


6 61 


5.29 


6.80 


5.45 


22.1 


4 . 89 


6 29 


5.04 


6 49 


5.20 


6 68 


5.35 


6,87 


5.5t 


22.2 


4.95 


6 36 


5.10 


6 56 


5.25 


6,75 


5.41 


6 94 


5.57 


22.3 


6.00 


6 43 


5.15 


6.63 


5.31 


6 82 


5.47 


7 01 


5.62 


22.4 


6.06 


6 50 


5.21 


6 70 


5.37 


6 89 


5.52 


7 08 


5.68 


22.5 


6.11 


6 57 


5.27 


6 77 


5.43 


6 96 


5.58 


7.16 


5.74 


22.0 


6.t7 


6 64 


5.33 


6.84 


5.48 


7,03 


5.64 


7 23 


5.80 


22.7 


6.2s 


6 71 


5.38 


6.91 


5.54 


7 10 


5.70 


7.31 


5.86 


22. S 


6.29 


6.78 


5.44 


6.99 


5.60 


7.17 


5.75 


7.38 


5.91 


22.0 



212 
6 



METHODS OF ANALYSIS 



[Chap. 



Table 17.— Alcohol 





17.5 


' C. 


18° 


C. 


19° 


C. 


20° 


C 


21° C. 


SCALE 
READING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


^y, 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


23.0 


5.99 


4.75 


6.08 


4.87 


6 28 


5.03 


6 47 


5.18 


6.67 


23.1 


6.06 


4.85 


6.15 


4.93 


6.35 


5.09 


6 54 


5.24 


6.74 


23.2 


6.13 


4.91 


6 22 


4.98 


6.42 


5.14 


6 61 


5.30 


6.81 


23.3 


6 20 


4.97 


6 29 


5.04 


6.49 


5.20 


6.68 


5.36 


6.88 


23.4 


6.27 


5.02 


6.36 


5.10 


6 56 


5.26 


6.75 


5.41 


6.95 


23.5 


6 34 


5.08 


6,43 


5.15 


6.63 


5.31 


6 83 


5 47 


7.02 


23.6 


6.41 


5.14 


6 50 


5.21 


6 70 


5.37 


6 90 


5.53 


7.09 


23.7 


6 48 


5.19 


6.57 


5.27 


6 78 


5.43 


6.97 


5.59 


7.16 


23.8 


6 55 


5.25 


6.64 


5.32 


6 85 


5.49 


7 04 


5.64 


7.23 


23.9 


6 62 


5.30 


6.71 


5.38 


6 92 


5.54 


7 11 


5.70 


7.31 


24.0 


6 69 


5.36 


6.78 


5.44 


6 99 


5.60 


7.18 


5.76 


7.38 


24.1 


6.76 


5.42 


6.85 


5.49 


7 06 


5.66 


7.25 


5.82 


7.46 


24.2 


6 83 


5.47 


6 92 


5.55 


7.13 


5.71 


7 32 


5.87 


7.52 


24.3 


6 90 


5.53 


6 99 


5.61 


7 20 


5.77 


7 39 


5.93 


7.69 


24.4 


6.97 


5.59 


7.06 


5.66 


7.27 


5.83 


7.46 


5.99 


7 66 


24.5 


7.04 


5.64 


7.13 


5.72 


7 34 


5.89 


7 53 


6.04 


7.73 


24.6 


7.11 


5.70 


7 20 


5.78 


7.41 


5.94 


7.60 


6.10 


7.80 


24.7 


7.18 


5.76 


7 27 


5.83 


7.48 


6.00 


7.67 


6.15 


7.86 


24.8 


7 25 


5.81 


7 35 


5.89 


7.55 


6.06 


7.74 


6.21 


7.93 


24.9 


7.32 


5.87 


7.42 


5.95 


7.62 


6.11 


7.81 


6.26 


8 00 


25.0 


7.39 


5.93 


7 49 


6.01 


7.68 


6.16 


7,88 


6.32 


8.06 


25.1 


7 46 


5.98 


7 56 


6.06 


7.75 


6.22 


7.94 


6.37 


8.13 


25.2 


7.53 


6.04 


7 63 


6.12 


7 82 


6.27 


8.01 


6.43 


8 20 


25.3 


7.59 


6.09 


7 69 


6.17 


7 89 


6.33 


8 07 


6.48 


8 27 


25.4 


7.66 


6.15 


7.76 


6.23 


7 95 


6.38 


8.14 


6.54 


8.34 


25.5 


7 73 


6.20 


7 83 


6.28 


8 02 


6.44 


8 21 


6.59 


8.41 


25.6 


7 80 


6.26 


7 90 


6.34 


8 09 


6.49 


8.28 


6.65 


8.48 


25.7 


7 87 


6.31 


7 96 


6.39 


8 16 


6.55 


8 35 


6.70 


8 66 


25.8 


7.94 


6.37 


8 03 


6.44 


8 22 


6.60 


8.42 


6.76 


8 62 


25.9 


8.00 


6.42 


8.10 


6.50 


8 29 


6.66 


8.48 


6.81 


8.69 


26.0 


8 07 


6.48 


8.16 


6.55 


8 36 


6.71 


8,55 


6.87 


8.76 


26.1 


8.14 


6.53 


8.23 


6.61 


8 43 


6.77 


8 62 


6.92 


8.82 


26.2 


8.21 


6.59 


8 30 


6.66 


8 50 


6.82 


8.69 


6.98 


8 89 


26.3 


8 27 


6.64 


8 37 


6.72 


8.57 


6.88 


8 75 


7.03 


8.96 


26.4 


8.34 


6.70 


8.44 


6.78 


8.63 


6.93 


8,82 


7.09 


9.03 


26.5 


8.41 


6.75 


8.50 


6.83 


8.70 


6.99 


8,89 


7.15 


9 10 


26.6 


8.48 


6.81 


8.57 


6.88 


8.77 


7.04 


8 96 


7.20 


9.16 


26.7 


8.55 


6.86 


8 64 


6.94 


8 84 


7.10 


9 03 


7.26 


9.23 


26.8 


8.62 


6.92 


8.71 


6.99 


8.91 


7.15 


9.10 


7.31 


9.30 


26.9 


8 68 


6.97 


8.78 


7.05 


8 98 


7.21 


9.17 


7.37 


9.37 


27.0 


8.75 


7.03 


8.85 


7.11 


9 05 


7.27 


9.23 


7.42 


9.44 


27.1 


8 82 


7.08 


8 91 


7.16 


9.11 


7.32 


9 30 


7.48 


9.61 


27.2 


8 89 


7.14 


8 98 


7.22 


9.18 


7.38 


9.37 


7.54 


9.58 


27.3 


8 95 


7.19 


9 05 


7.27 


9 25 


7.43 


9.44 


7.59 


9.66 


27.4 


9.02 


7.25 


9.12 


7.33 


9.32 


7.49 


9.61 


7.65 


9.71 


27.5 


9 09 


7.30 


9.19 


7.38 


9 38 


7.54 


9.58 


7.70 


9.78 


27.6 


9 16 


7.36 


9.26 


7.44 


9 45 


7.60 


9.65 


7.76 


9 86 


27.7 


9 22 


7.41 


9 32 


7.49 


9.52 


7.65 


9.72 


7.82 


9.91 


27.8 


9.29 


7.47 


9.39 


7.55 


9.59 


7.71 


9.79 


7.87 


9.98 


27 9 


9 36 


7.62 


9.46 


7.60 


9.65 


7.76 


9.86 


7.93 


10.05 



XVI] 



WINES 



213 



Table. — Continued. 



21° C. 


22° 


c. 


23° 


c. 


24° 


c. 


25° 


c. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
READING 


by 


by 


by 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




5.3i 


6.86 


5.50 


7.06 


5.66 


7.24 


5.81 


7.45 


5.97 


23.0 


5.A0 


6 93 


5.56 


7.13 


5.71 


7.32 


5.87 


7.52 


6.03 


23.1 


5.46 


7.00 


5.61 


7.20 


5.77 


7 39 


5.93 


7.59 


6.08 


23.2 


5.51 


7.07 


5.67 


7.27 


5.83 


7.46 


5.98 


7 66 


6.14 


23.3 


5.57 


7.14 


5.73 


7.34 


5.89 


7.53 


6.04 


7.73 


6.20 


23.4 


5.63 


7.21 


5.78 


7.41 


5.94 


7.60 


6.10 


7.80 


6.25 


23.5 


5.69 


7.28 


5.84 


7.48 


6.00 


7.67 


6.15 


7.87 


6.31 


23.6 


5.74 


7.35 


5.89 


7.55 


6.06 


7 74 


6.21 


7.94 


6.37 


23.7 


5.80 


7.42 


5.95 


7.62 


6.11 


7.81 


6.27 


8.00 


6.42 


23.8 


5.86 


7.49 


6.01 


7.69 


6.17 


7.88 


6.32 


8.07 


6.48 


23.9 


5.92 


7.56 


6.07 


7.76 


6.22 


7.96 


6.38 


8.14 


6.53 


24.0 


5.97 


7.63 


6.12 


7.83 


6.28 


8.02 


6.44 


8,21 


6.59 


24.1 


6.08 


7.70 


6.18 


7.90 


6.34 


8 09 


6.49 


8.28 


6.65 


24.2 


6.08 


7.77 


6.24 


7.97 


6.39 


8.16 


6.55 


8 35 


6.70 


24.3 


6.14 


7.84 


6.29 


8.04 


6.45 


8.23 


6.60 


8.42 


6.76 


24.4 


6.20 


7 91 


6.35 


8.10 


6.50 


8 30 


6.66 


8.48 


6.81 


24.5 


6.25 


7.98 


6.41 


8.17 


6.56 


8 37 


6.72 


8.55 


6.87 


24.6 


6.31 


8 05 


6.46 


8.24 


6.62 


8.44 


6.77 


8.62 


6.93 


24.7 


6.36 


8 12 


6.52 


8.31 


6.67 


8.51 


6.83 


8 69 


6.98 


24.8 


6.42 


8 19 


6.58 


8.38 


6.73 


8.58 


6.89 


8.76 


7.04 


24.9 


6.47 


8 26 


6.63 


8.45 


6.79 


8.64 


6.94 


8,84 


7.10 


25.0 


6.53 


8 33 


6.69 


8.52 


6.84 


8.71 


7.00 


8,91 


7.15 


25.1 


6.59 


8.40 


6.75 


8.59 


6.90 


8.78 


7.06 


8 98 


7.21 


25.2 


6.64 


8.47 


6.80 


8.66 


6.96 


8 85 


7.11 


9 05 


7.27 


25.3 


6.70 


8.54 


6.86 


8.73 


7.01 


8.92 


7.17 


9,12 


7.33 


25.4 . 


6.75 


8 61 


6.92 


8,80 


7.07 


8 99 


7.23 


9,19 


7.38 


25.5 


6.81 


8 68 


6.97 


8 86 


7.12 


9 06 


7.28 


9 26 


7.44 


25.6 


6.87 


8 75 


7.03 


8 93 


7.18 


9 13 


7.34 


9,33 


7.50 


25.7 


6 92 


8 82 


7.08 


9.00 


7.23 


9 20 


7.40 


9 39 


7.55 


25,8 


6.98 


8 89 


7.14 


9.07 


7.29 


9.27 


7.45 


9,46 


7.61 


25,9 


7.03 


8.95 


7.19 


9.14 


7.35 


9 34 


7.51 


9 53 


7.67 


26,0 


7.09 


9 02 


7.25 


9.21 


7.40 


9.41 


7.56 


9,60 


7.73 


26.1 


7.14 


9 09 


7.30 


9.28 


7.46 


9 48 


7.62 


9 67 , 


7.78 


26.2 


7.20 


9 16 


7.36 


9 35 


7.51 


9.55 


7.68 


9.74 


7.84 


26.3 


7.25 


9.22 


7.41 


9.42 


7.57 


9.61 


7.73 


9,81 


7.90 


26.4 


7.31 


9 29 


7.47 


9.49 


7.63 


9 68 


7.79 


9 88 


7.95 


26.5 


7.36 


9.36 


7.52 


9.55 


7.68 


9.75 


7.85 


9 95 


8.01 


26.6 


7.42 


9 43 


7.58 


9 62 


7.74 


9.82 


7.90 


10 02 


8.07 


26.7 


7.47 


9 49 


7.63 


9 69 


7.79 


9 89 


7.96 


10 09 


8.12 


26.8 


7.53 


9.56 


7.69 


9.76 


7.85 


9.96 


8.02 


10,16 


8.18 


26.9 


7.59 


9.63 


7.74 


9 83 


7.91 


10.03 


8.07 


10 23 


8.24 


27.0 


7.65 


9.70 


7.80 


9.90 


7.96 


10 10 


8.13 


10 30 


8.29 


27.1 


7.70 


9.76 


7.85 


9.97 


8.02 


10.17 


8.18 


10,37 


8.35 


27 2 


7.76 


9.83 


7.91 


10 03 


8.07 


10.24 


8.24 


10,44 


8.40 


27.3 


7.81 


9.90 


7.96 


10.10 


8.13 


10.31 


8.30 


10,51 


8.46 


27.4 


7.86 


9 97 


8.02 


10.17 


8.18 


10.38 


8.35 


10.58 


8.52 


27.5 


7.92 


10.03 


8.07 


10.24 


8.24 


10.45 


8.41 


10.65 


8.57 


27.6 


7.97 


10.10 


8.13 


10.31 


8.30 


10 51 


8.46 


10.72 


8.63 


27.7 


8.03 


10.17 


8.18 


10.38 


8.S5 


10.58 


8.52 


10.79 


8.69 


27.8 


8.08 


10.24 


8.24 


10.45 


8.41 


10.65 


8.58 


10.86 


8.74 


27.9 



214 



METHODS OF ANALYSIS 



[Chap. 



Table 17.— Alcohol 





17,5 


"C, 


18 


C. 


19° 


C. 


20 


'C. 


2l°C. 


SCALE 
READING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


^y. 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


28.0 


9 43 


7.58 


9 53 


7.66 


9 72 


7.82 


9 92 


7.98 


10 12 


28.1 


9 50 


7.64 


9 59 


7.71 


9 79 


7.87 


9 99 


8.04 


10,18 


28.2 


9 57 


7.69 


9 66 


7.77 


9 86 


7.93 


10 06 


8.09 


10 25 


28.3 


9 64 


7.75 


9 73 


7.82 


9 92 


7.98 


10 13 


8.15 


10 32 


28.4 


9 70 


7.80 


9 80 


7.88 


9 99 


8.04 


10,19 


8.20 


10 39 


28.5 


9 77 


7.86 


9 86 


7.93 


10 06 


8.09 


10 26 


8.26 


10 45 


28.6 


9 84 


7.91 


9 93 


7.99 


10 13 


8.15 


10 32 


8.31 


10 52 


28.7 


9 91 


7.97 


10 00 


8.04 


10 19 


8.20 


10 39 


8.36 


10,59 


28.8 


9 97 


8.02 


10 07 


8.10 


10 26 


8.26 


10 46 


8.42 


10.66 


28.9 


10 04 


8.08 


10 13 


8.15 


10 32 


8.31 


10 52 


8.47 


10.73 


29.0 


10 10 


8 13 


10 19 


8.20 


10 39 


8.36 


10 59 


8.53 


10.79 


29.1 


10 17 


8.18 


10 26 


8.26 


10 46 


8.42 


10 66 


8.58 


10 86 


29,2 


10 24 


8.24 


10 33 


8.31 


10 52 


8.47 


10 73 


8.64 


10 93 


29.3 


10 30 


8.29 


10 40 


8.37 


10 59 


8.53 


10 79 


8.69 


11.00 


29.4 


10 36 


8.34 


10,46 


8.42 


10 66 


8.58 


10 86 


8.74 


11.06 


29.5 


10 43 


8.40 


10 52 


8.47 


10 73 


8.64 


10 93 


8.80 


11.13 


29.6 


10 50 


8.45 


10 59 


8 . 53 


10 79 


8.69 


10 99 


8.85 


11 20 


29.7 


10 56 


8.50 


10 66 


8.58 


10 86 


8.74 


11 06 


8.91 


11 27 


29.8 


10 63 


8.56 


10 72 


8.63 


10 93 


8.80 


11 12 


8.96 


11 33 


29.9 


10 69 


8.61 


10 79 


8.69 


10 99 


8.85 


11 19 


9.02 


11 39 


30.0 


10 76 


8.66 


10 86 


8.74 


11 06 


8.91 


11 26 


9.07 


11.46 


30.1 


10 83 


8.72 


10 93 


8.80 


11 12 


8.96 


11 32 


9.12 


11 52 


30.2 


10 89 


8.77 


10 99 


8.85 


11 18 


9.02 


11 38 


9.18 


11 59 


30.3 


10 95 


8.82 


11 05 


8.90 


11 25 


9.07 


11 45 


9.23 


11 66 


30.4 


11 02 


8.88 


11 12 


8.96 


11 31 


9.12 


11 51 


9.28 


11.72 


30.5 


11 08 


8.9S 


11 18 


9.01 


11 38 


9.18 


11.58 


9.34 


11 79 


30.6 


11 15 


8.98 


11 25 


9.06 


11 44 


9.23 


11 64 


9.39 


11 85 


30.7 


11 21 


9.04 


11 31 


9.12 


11 51 


9.28 


11 71 


9.44 


11 92 


30.8 


11 28 


9.09 


11 38 


9.17 


11,58 


9.34 


11,78 


9.50 


11 99 


30.9 


11 34 


9.14 


11,44 


9.22 


11 64 


9.39 


11 84 


9.55 


12.05 


31.0 


11 41 


9.19 


11 51 


9.28 


11 71 


9.44 


11,91 


9.60 


12 12 


31.1 


11 47 


9.25 


11 57 


9.33 


11,77 


9.49 


11 97 


9.66 


12.18 


31.2 


11 64 


9.30 


11 64 


9.38 


11 84 


9.55 


12 04 


9.71 


12 25 


31.3 


11 60 


9.35 


11 70 


9.43 


11 90 


9.60 


12,11 


9.76 


12 32 


31.4 


11.66 


9.40 


11,77 


9.49 


11 97 


9.65 


12 17 


9.82 


12 38 


31.5 


11 73 


9.46 


11 83 


9.5i 


12 03 


9.71 


12 24 


9.87 


12 45 


31.6 


11.79 


9.51 


11 90 


9.59 


12 10 


9.76 


12 30 


9.92 


12 51 


31.7 


11 86 


9.56 


11 96 


9.65 


12 16 


9.81 


12 37 


9.98 


12,58 


31.8 


11 92 


9.62 


12 03 


9.70 


12 23 


9.87 


12 43 


10.03 


12,64 


31.9 


11.99 


9.67 


12.09 


9.75 


12 29 


9.92 


12 50 


10.09 


12,71 


32.0 


12 05 


9.72 


12 15 


9 . SO 


12,36 


9.97 


12 57 


10.14 


12 78 


32,1 


12.12 


9.77 


12 21 


9.86 


12 42 


10.03 


12 63 


10.19 


12,84 


32.2 


12 18 


9.83 


12 28 


9.91 


12,49 


10.08 


12 70 


10.25 


12 91 


32,3 


12,24 


9.88 


12 34 


9.96 


12 55 


10.13 


12 76 


10.30 


12 97 


32.4 


12 31 


9.93 


12,40 


10.02 


12,62 


10.19 


12,83 


10.35 


13.04 


32,5 


12 37 


9.98 


12,47 


10.07 


12 68 


10.24 


12 89 


10.41 


13,10 


32.6 


12 43 


10.04 


12 54 


10.12 


12,75 


10.29 


12 96 


10.46 


13,17 


32.7 


12,50 


10.09 


12 60 


10.17 


12 81 


10.34 


13 03 


10.52 


13,24 


32.8 


12 56 


10.14 


12.67 


10.23 


12 88 


10.40 


13,09 


10.57 


13 30 


32.9 


12 62 


10.19 


12,73 


10.28 


12,94 


10.45 


13,15 


10.62 


13 37 



XVII 



Table. — Continued. 



WINES 



215 
6 



21° C. 


22' 


C. 


23° 


C. 


24° 


C. 


25° 


C. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
RBADINQ 


by 


by 


by 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




8.14 


10 31 


8.30 


10 51 


8.46 


10 72 


8 . 63 


10 93 


8.80 


28.0 


8.19 


10 38 


8.35 


10 58 


8.62 


10 79 


8 . 60 


10 99 


8.86 


28.1 


8.35 


10 45 


8.41 


10 65 


8.58 


10 86 


8.74 


11.06 


8.91 


28.2 


8. SO 


10 62 


8.46 


10 72 


8.63 


10 93 


8.80 


11 13 


8.97 


28^3 


8. 36 


10 59 


8.52 


10 79 


8.69 


11 00 


8.86 


11 20 


9.02 


28.4 


8.41 


10 66 


8.58 


10 86 


8.74 


11 06 


8.91 


11 27 


0.08 


28.5 


8.47 


10 72 


8.63 


10 93 


8.80 


11 13 


8.07 


11 33 


0.13 


28.6 


8.62 


10 79 


8.69 


11 00 


8.86 


11 20 


0.02 


11 40 


9.19 


28.7 


8.68 


10 86 


8.74 


11 06 


8.91 


11 27 


0.08 


11 47 


9.24 


28.8 


8.64 


10 93 


8.80 


11 13 


8.97 


11 33 


0.13 


11 54 


9.30 


28.9 


8.69 


11 00 


8.86 


11 20 


9.02 


11 40 


0.10 


11 61 


9.36 


20.0 


8.75 


11 06 


8.91 


11 27 


9.08 


11 47 


0.24 


11 68 


9.41 


29.1 


8.80 


11 13 


8.97 


11 33 


9.13 


11 54 


0.30 


11 75 


9.47 


29.2 


8.86 


11 20 


9.02 


11 40 


9.19 


11 60 


9.35 


11 81 


9.62 


29.. 3 


8.91 


11 27 


9.08 


11 47 


9.24 


11.67 


9.41 


11.88 


9.68 


29.4 


8.97 


11 33 


9.13 


11 54 


9.30 


11 74 


9.46 


11 94 


9.63 


29.5 


9.02 


11 39 


9.18 


11 60 


9.35 


11 81 


9.52 


12 01 


9.69 


29 . f) 


9.08 


11 46 


9.24 


11 67 


9.41 


11 87 


9.57 


12 08 


9.75 


29.7 


9.13 


11 53 


9.29 


11 74 


9.46 


11 94 


0.63 


12.15 


9.80 


29.8 


9.18 


11 60 


9.35 


11.81 


9.52 


12 01 


0.60 


12 22 


9.86 


29.9 


9.24 


11 66 


9.40 


11 87 


9.57 


12 08 


0.74 


12 29 


9.91 


30.0 


9.29 


11 73 


9.46 


11 93 


9.63 


12 14 


9.80 


12 36 


9.97 


30.1 


9.34 


11 79 


9.51 


12 00 


9.68 


12 21 


9.85 


12 42 


10.02 


30.2 


9.40 


11 86 


9.57 


12 07 


9.74 


12 28 


0.01 


12 49 


10.08 


30.3 


9.46 


11 93 


9.62 


12 13 


9.70 


12 34 


0(i 


12 56 


10.13 


30.4 


9.50 


11 99 


9.67 


12 20 


9.85 


12 41 


10.02 


12 63 


10.19 


30.5 


9.66 


12.06 


9.73 


12 27 


9.90 


12 48 


10.07 


12 70 


10.24 


30.6 


9.61 


12 13 


9.78 


12 34 


9.96 


12 65 


10.13 


12 77 


10.30 


30.7 


9.67 


12 19 


9.84 


12 40 


10.01 


12 61 


10.18 


12 84 


10.36 


30.8 


9.72 


12 26 


9.89 


12 47 


10.07 


12 68 


10.24 


12 90 


10.41 


30.9 


9.77 


12 32 


9.95 


12 54 


10.12 


12 75 


10.20 


12 97 


10.47 


31.0 


9.83 


12 39 


10.00 


12 60 


10.17 


12 82 


10.35 


13 04 


10.62 


31.1 


9.88 


12 46 


10.05 


12 67 


10.23 


12 89 


10.40 


13 11 


10.58 


31.2 


9.94 


12.62 


10.11 


12 74 


10.28 


12 96 


10.46 


13 17 


10.63 


31.3 


9.99 


12 59 


10.16 


12 81 


10.34 


13 02 


10.61 


13 24 


10.69 


31.4 


10.04 


12 66 


10.22 


12 87 


10.39 


13 09 


10.57 


13 31 


10.74 


31.5 


10.10 


12 72 


10.27 


12.94 


10.45 


13 15 


10.62 


13 37 


10.80 


31.6 


10.15 


12 79 


10.32 


13 01 


10.50 


13 22 


10.68 


13 44 


10.86 


31.7 


10.21 


12 85 


10.38 


13 07 


10.55 


13 29 


10.73 


13 51 


10.91 


31.8 


10.26 


12 92 


10.43 


13 14 


10.61 


13 35 


10.78 


13 57 


10.97 


31.9 


10.31 


12 99 


10.49 


13 20 


10.66 


13 42 


10.84 


13 64 


11.02 


32.0 


10.37 


13 05 


10.64 


13.27 


10.72 


13.49 


10.00 


13 71 


11.08 


32.1 


10.42 


13 12 


10.59 


13 34 


10.77 


13 55 


10.05 


13 77 


11.13 


32.2 


10.48 


13 18 


10.65 


13 40 


10.83 


13 62 


11.01 


13 84 


11.19 


32^3 


10.63 


13 25 


10.70 


13.47 


10.88 


13 69 


11.06 


13.91 


11.24 


32.4 


10.58 


13 32 


10.76 


13 53 


10.04 


13 76 


11.11 


13 97 


11.30 


32.5 


10.64 


13 38 


10.81 


13.60 


10.90 


13 82 


11.17 


14.04 


11.35 


32.6 


10.69 


13 45 


10.87 


13 66 


11.04 


13 89 


11.22 


14.11 


11.41 


32.7 


10.75 


13 51 


10.92 


13.73 


It .10 


13 95 


11.28 


14.17 


11.46 


32.8 


10.80 


13 58 


10.97 


13.80 


11.15 


14.02 


11.33 


14.24 


11.52 


32.9 



216 
6 



METHODS OF ANALYSIS 



[Chap. 



Table 17. — Alcohol 





17.5 


"C. 


18' 


C. 


19 


C. 


20 


•c. 


21° C. 


SCALE 
READING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


33.0 


12 69 


10.24 


12.79 


10.33 


13.01 


10.50 


13.22 


10.68 


13 43 


33.1 


12.76 


10.30 


12 86 


10.38 


13.07 


10.56 


13.28 


10.73 


13.60 


33.2 


12.82 


10.35 


12.92 


10.43 


13.13 


10.61 


13 36 


10.79 


13.66 


33.3 


12 88 


10.40 


12.99 


10.49 


13.20 


10.66 


13.41 


10.84 


13.63 


33.4 


12.95 


10.45 


13 06 


10.54 


13.26 


10.71 


13.48 


10.89 


13.69 


33.5 


13.01 


10.50 


13.11 


10.59 


13.32 


10.77 


13.64 


10.95 


13.76 


33.6 


13.08 


10.56 


13 18 


10.64 


13 39 


10.82 


13.61 


11.00 


13.82 


33.7 


13.14 


10.61 


13.24 


10.70 


13.46 


10.87 


13.67 


11.05 


13 89 


33.8 


13 20 


10.66 


13 30 


10.75 


13 52 


10.93 


13.74 


11.10 


13.95 


33.9 


13.26 


10.71 


13 37 


10.80 


13,68 


10.98 


13.80 


11.16 


14.02 


34.0 


13 33 


10.77 


13.43 


10.85 


13 64 


11.03 


13.86 


11.21 


14.08 


34.1 


13 39 


10.82 


13.49 


10.91 


13.71 


11.08 


13 93 


11.26 


14.16 


34.2 


13.45 


10.87 


13.66 


10.96 


13.77 


11.13 


13 99 


11.31 


14.21 


34.3 


13.62 


10.92 


13 62 


11.01 


13 83 


11.19 


14.06 


11.36 


14.27 


34.4 


13.58 


10.97 


13.68 


11.06 


13.90 


11.24 


14.12 


11.41 


14.34 


34.5 


13.64 


11.03 


13.76 


11.11 


13 96 


11.29 


14.18 


11.47 


14.40 


34.6 


13.70 


11.08 


13 81 


11.16 


14.02 


11.34 


14.25 


11.52 


14 47 


34.7 


13.77 


11.13 


13.87 


11.22 


14.08 


11.39 


14.31 


11.57 


14.53 


34.8 


13 83 


11.18 


13.94 


11.27 


14 14 


11.44 


14 37 


11.62 


14.69 


34.9 


13 89 


11.23 


14.00 


11.32 


14.20 


11.49 


14.43 


11.67 


14.66 


35.0 


13.96 


11.28 


14 06 


11.37 


14.27 


11.55 


14 60 


11.73 


14.72 


35.1 


14.02 


11.33 


14.13 


11.42 


14 33 


11.60 


14.66 


11.78 


14.78 


35.2 


14.08 


11.38 


14.19 


11.47 


14 39 


11.65 


14.62 


11.83 


14.86 


35.3 


14.14 


11.44 


14 26 


11.52 


14.46 


11.70 


14.69 


11.88 


14.91 


35.4 


14.21 


11.49 


14.31 


11.57 


14.62 


11.75 


14.76 


11.93 


14.97 


35.5 


14.27 


11.54 


14.38 


11.63 


14.69 


11.81 


14.81 


11.99 


15.04 


35.6 


14.33 


11.59 


14.44 


11.68 


14.66 


11.86 


14.87 


12.04 


16.10 


35.7 


14.39 


11.64 


14.60 


11.73 


14.71 


11.91 


14.94 


12.09 


16 16 


35.8 


14.46 


11.69 


14.66 


11.78 


14 78 


11.96 


16.00 


12.14 


16 23 


35.9 


14.52 


11.74 


14.63 


11.83 


14.84 


12.01 


16.06 


12.19 


15 29 


36.0 


14.68 


11.79 


14 69 


11.88 


14.90 


12.06 


16.13 


12.24 


16.36 


36.1 


14.64 


11.85 


14 76 


11.94 


14.97 


12.11 


16.19 


12.30 


16.42 


36.2 


14.71 


11.90 


14.81 


11.99 


16 03 


12.16 


16.26 


12.35 


15.48 


36.3 


14.77 


11.95 


14.88 


12.04 


15.09 


12.22 


16.32 


12.40 


15.64 


36.4 


14.83 


12.00 


14.94 


12.09 


16.16 


12.27 


16.38 


12.45 


16.61 


36.5 


14.89 


12.05 


15 00 


12.14 


16 22 


12.32 


16.44 


12.50 


15.67 


36.6 


14.96 


12.10 


16.06 


12.19 


16.28 


12.37 


16.61 


12.56 


16.73 


36.7 


15.02 


12.15 


16.13 


12.24 


16.36 


12.42 


16.67 


12.61 


16.80 


36.8 


15.08 


12.20 


15.19 


12.29 


16.41 


12.47 


16.63 


12.66 


16.86 


36.9 


15.14 


12.25 


15.26 


12.34 


16.47 


12.53 


15.70 


12.71 


15.92 


37.0 


15 20 


12.30 


16.31 


12.40 


16 63 


12.58 


16.76 


12.77 


16.99 


37.1 


15 27 


12.36 


16 38 


12.45 


16 60 


12.63 


16.82 


12.82 


16 06 


37.2 


15.33 


12.41 


16.44 


12.50 


16 66 


12.68 


15.89 


12.87 


16.11 


37.3 


15.39 


12.46 


16.60 


12.55 


15.72 


12.73 


15.96 


12.92 


16.18 


37.4 


16.45 


12.51 


16.66 


12.60 


16.79 


12.78 


16.01 


12.97 


16.24 


37.5 


16 51 


12.56 


16.63 


12.65 


16.86 


12.84 


16.08 


13.03 


16 30 


37.6 


15.57 


12.61 


16.69 


12.70 


15.91 


12.89 


16.14 


13.08 


16.37 


37.7 


15.64 


12.66 


16.76 


12.75 


16.97 


12.94 


16 20 


13.13 


16.43 


37.8 


16.70 


12.71 


16.81 


12.81 


16.04 


12.99 


16.26 


13.18 


16.49 


37.9 


16.76 


12.76 


16 88 


12.86 


16.10 


13.04 


16.33 


13.23 


16.66 



XVI] 



Table. — Continued. 



WINES 



217 
6 



21° C. 


22° 


C. 


23° 


c. 


24 


c. 


25 


c. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
READING 


by 


by 


by 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




10.85 


13.64 


11.03 


13.86 


11.21 


14.09 


11.39 


14 31 


11.57 


33.0 


10.91 


13.71 


11.08 


13.93 


11.26 


14.16 


11.44 


14.38 


11.63 


33.1 


10.96 


13.78 


11.13 


13 99 


11.31 


14.22 


11.49 


14.44 


11.68 


33.2 


11.02 


13.84 


11.19 


14.06 


11.37 


14.28 


11.55 


14.51 


11.74 


33.3 


11.07 


13.91 


11.24 


14.13 


11.42 


14.36 


11.60 


14.58 


11.79 


33.4 


11.12 


13.97 


11.29 


14.19 


11.48 


14.42 


11.66 


14.64 


11.85 


33.5 


11.17 


14.04 


11.35 


14.26 


11.53 


14.48 


11.71 


14.71 


11.90 


33.6 


11.23 


14.11 


11.40 


14.32 


11.58 


14.55 


11.77 


14.78 


11.96 


33.7 


11.28 


14.17 


11.45 


14.39 


11.64 


14.62 


11.82 


14.85 


12.01 


33.8 


11.33 


14.24 


11.51 


14.45 


11.69 


14.68 


11.88 


14.91 


12.07 


33.9 


11.38 


14.30 


11.56 


14.52 


11.75 


14.75 


11.93 


14.98 


12.12 


34.0 


11. U 


14.37 


11.61 


14.59 


11.80 


14.81 


11.98 


15.05 


12.18 


34.1 


11.49 


14.43 


11.67 


14.65 


11.85 


14.88 


12.04 


15.11 


12.23 


34.2 


11.54 


14.50 


11.72 


14.72 


11.91 


14.95 


12.09 


15.18 


12.29 


34.3 


11.59 


14.57 


11.78 


14.78 


11.96 


16.01 


12.15 


15.25 


12.34 


34.4 


11.65 


14.63 


11.83 


14.85 


12.02 


15.08 


12.20 


15 31 


12.40 


34.5 


11.70 


14.70 


11.88 


14.91 


12.07 


16.14 


12.26 


16.38 


12.45 


34.6 


11.75 


14.76 


11.94 


14 98 


12.12 


16 21 


12.31 


15.45 


12.51 


34.7 


11.81 


14.83 


11.99 


15.05 


12.18 


16.28 


12.36 


16.61 


12.56 


34.8 


11.86 


14.89 


12.04 


15.11 


12.23 


16 34 


12.42 


16.58 


12.62 


34.9 


11.91 


14.96 


12.10 


15.18 


12.28 


15.41 


12.47 


15 66 


12.67 


35.0 


11.96 


15.03 


12.15 


15.24 


12.34 


15.47 


12.53 


16.71 


12.73 


35.1 


12.02 


15.09 


12.20 


15.31 


12.39 


15 54 


12.58 


15 78 


12.78 


35.2 


12.07 


15.15 


12.25 


15.37 


12.44 


16.61 


12.64 


16,85 


12.84 


35.3 


12.12 


15.22 


12.31 


15.44 


12.50 


16 67 


12.69 


15.91 


12.89 


35.4 


12.17 


15.28 


12.36 


15 50 


12.55 


15.74 


12.75 


15.98 


12.95 


35.5 


12.23 


16.34 


12.41 


15.56 


12.60 


15.80 


12.80 


16.06 


13.00 


35.6 


12.28 


15.41 


12.47 


15.63 


12.66 


15.87 


12.85 


16.11 


13.05 


35.7 


12.33 


15.47 


12.52 


15.69 


12.71 


16.93 


12.91 


16.18 


13.11 


35.8 


12.38 


16.63 


12.57 


15.76 


12.76 


16.00 


12.96 


16.24 


13.16 


35.9 


12.43 


15.69 


12.62 


15.82 


12.82 


16 06 


13.02 


16.31 


13.21 


36.0 


12.49 


15.66 


12.68 


15 89 


12.87 


16.13 


13.07 


16.37 


13.27 


36.1 


12.54 


16.72 


12.73 


15.95 


12.92 


16.19 


13.12 


16.44 


13.32 


36.2 


12.59 


16.78 


12.78 


16.02 


12.98 


16.26 


13.18 


16.50 


13.37 


36.3 


12.64 


15 86 


12.84 


16.08 


13.03 


16.32 


13.23 


16.66 


13.43 


36.4 


12.70 


15.91 


12.89 


16.15 


13.08 


16 39 


13.28 


16 63 


13.48 


36.5 


12.75 


15 97 


12.94 


16 21 


13.14 


16.46 


13.34 


16.69 


13.53 


36.6 


12.80 


16.04 


12.99 


16 28 


13.19 


16.52 


13.39 


16.76 


13.59 


36.7 


12.85 


16 10 


13.05 


16 34 


13.24 


16.58 


13. U 


16.82 


13.64 


36.8 


12.91 


16.16 


13.10 


16.40 


13.29 


16.65 


13.49 


16.89 


13.70 


36.9 


12.96 


16 23 


13.15 


16.47 


13.35 


16.71 


13.55 


16.95 


13.75 


37.0 


13.01 


16.29 


13.20 


16.53 


13.40 


16.77 


13.60 


17.02 


13.80 


37.1 


13.06 


16.35 


13.26 


16.60 


13.45 


16.84 


13.65 


17.08 


13.86 


37.2 


13.11 


16.42 


13.31 


16.66 


13.50 


16.90 


13.71 


17.15 


13.91 


37.3 


13.16 


16.48 


13.36 


16.72 


13.56 


16.97 


13.76 


17.21 


13.96 


37.4 


13.21 


16.54 


13.41 


16.79 


13.61 


17.03 


13.81 


17.27 


14-02 


37.5 


13.27 


16.61 


13.46 


16.85 


13.66 


17.09 


13.87 


17.34 


14.07 


37.6 


13.32 


16.67 


13.52 


16.92 


13.72 


17.16 


13.92 


17.40 


14.12 


37.7 


13.37 


16.73 


13.57 


16.98 


13.77 


17.22 


13.97 


17.46 


14.17 


37.8 


13.42 


16.80 


13.62 


17.04 


13.82 


17.28 


14.03 


17.53 


14.23 


37.9 



218 



METHODS OF ANALYSIS 



[Chap. 



6 














Table 17.— 


Alcohol 




17.5 


'C. 


18° 


C. 


19° 


c. 


20° 


c. 


zrc. 


SCALE 
READING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


38.0 


15 82 


12.81 


15 94 


12.91 


16 16 


13.09 


16 39 


13.28 


16 62 


38.1 


15 88 


12.86 


16 00 


12.96 


16 22 


13.14 


16 45 


13.33 


16 68 


38.2 


15 94 


12.91 


16 06 


13.01 


16.29 


13.19 


16.51 


13.38 


16.75 


38.3 


16.01 


12.96 


16 12 


13.06 


16 35 


13.25 


16 57 


13.44 


16 81 


38.4 


16 07 


13.02 


16.18 


13.11 


16.41 


13.30 


16.64 


13.49 


16.87 


38.5 


16 13 


13.07 


16 25 


13.16 


16.47 


13.35 


16 70 


13.54 


16 94 


38.6 


16 19 


13.12 


16 31 


13.21 


16 53 


13.40 


16 76 


13.59 


17.00 


38.7 


16 25 


13.17 


16 37 


13.26 


16 60 


13.45 


16 83 


13.64 


17 06 


38.8 


16 31 


13.22 


16 43 


13.31 


16.66 


13.50 


16 89 


13.69 


17 13 


38.9 


16 37 


13.27 


16 49 


13.37 


16.72 


13.65 


16 95 


13.74 


17.19 


39.0 


16 44 


13.32 


16 55 


13.42 


16.78 


13.61 


17.01 


13.79 


17.26 


39.1 


16 50 


13.37 


16 61 


13.47 


16 84 


13.66 


17 07 


13.85 


17.31 


39.2 


16 56 


13.42 


16 67 


13.52 


16 91 


13.71 


17 14 


13.90 


17.38 


39.3 


16.62 


13.47 


16 74 


13.57 


16 97 


13.76 


17 20 


13.95 


17.44 


39.4 


16.68 


18.52 


16 80 


13.62 


17.03 


13.81 


17.26 


14-00 


17.60 


39.5 


16 74 


13.57 


16 86 


13.67 


17 09 


13.86 


17.32 


14-05 


17.56 


39.6 


16 80 


13.62 


16.92 


13.72 


17 15 


13.91 


17.39 


14.10 


17.63 


39.7 


16 87 


13.68 


16 98 


13.77 


17 21 


13.96 


17.45 


14.15 


17.69 


39.8 


16 93 


13:73 


17.04 


13.82 


17 28 


14.02 


17.51 


14.21 


17.75 


39.9 


16 99 


13.78 


17.10 


13.87 


17 34 


14-07 


17.57 


14-26 


17.81 


40.0 


17 05 


13.83 


17.16 


13.92 


17 40 


14-12 


17 63 


14-31 


17 88 


40.1 


17 11 


13.88 


17 23 


13.98 


17 46 


14-17 


17.70 


14-36 


17.94 


40.2 


17 17 


13.93 


17 29 


14-03 


17 52 


14-22 


17.76 


14-41 


18 00 


40.3 


17 23 


13.98 


17 35 


14-08 


17 58 


14-27 


17 82 


14-46 


18 06 


40.4 


17 29 


14.03 


17.41 


14-13 


17.64 


14-32 


17 88 


14-51 


18 12 


40.5 


17 35 


14 08 


17 47 


14-18 


17 71 


14-37 


17.94 


14-56 


18.19 


40.6 


17 41 


14.13 


17 53 


14-23 


17.77 


14-42 


18.01 


14-62 


18 25 


40.7 


17 48 


14-18 


17 59 


14-28 


17 83 


14-47 


18 07 


14-67 


18 31 


40.8 


17 54 


14-23 


17.66 


14-33 


17 89 


14-52 


18 13 


14-72 


18 37 


40.9 


17 60 


14-28 


17 71 


14-38 


17 95 


14-57 


18 19 


14-77 


18 43 


41.0 


17 66 


14-33 


17 77 


14-43 


18 01 


14-62 


18 26 


14-82 


18.49 


41.1 


17 72 


14-38 


17 84 


14-48 


18 07 


14.68 


18 31 


14-87 


18 56 


41.2 


17.78 


14-43 


17 90 


14.53 


18 13 


14-73 


18 37 


14-92 


18 62 


41.3 


17.84 


14-48 


17 96 


14-58 


18 20 


14-78 


18 44 


14-97 


18 68 


41.4 


17.90 


14-53 


18 03 


14-63 


18 26 


14.83 


18 60 


15.03 


18.74 


41.5 


17 96 


14-58 


18 08 


14.68 


18 32 


14-88 


18 56 


15.08 


18 80 


41.6 


18.02 


14-63 


18 14 


14-73 


18 38 


14-93 


18 62 


15.13 


18 86 


41.7 


18 08 


14-68 


18 20 


14-78 


18 44 


14-98 


18.68 


16.18 


18 93 


41.8 


18 14 


14.73 


18 26 


14-83 


18 50 


15.03 


18.74 


15.23 


18 99 


41.9 


18 20 


14-78 


18 32 


14-88 


18 56 


15.08 


18 81 


15.28 


19.05 


42.0 


18 27 


14-83 


18 38 


14-93 


18.62 


15.13 


18 87 


15.38 


19.11 


42.1 


18 33 


14-88 


18.44 


14-98 


18 68 


15.18 


18 93 


16.38 


19 17 


42.2 


18 39 


14-93 


18 50 


15.03 


18 74 


15.23 


18 99 


16. 43 


19 23 


42.3 


18 45 


14.98 


18.56 


15.08 


18 80 


15.28 


19.05 


15.48 


19 29 


42.4 


18.51 


15.03 


18.62 


15.13 


18.87 


15.33 


19 11 


15.53 


19 36 


42.5 


18.57 


15.08 


18.68 


15.18 


18 93 


15.38 


19.17 


16.58 


19 42 


42.6 


18 63 


15.13 


18.75 


15.23 


18 99 


15.43 


19.23 


16.63 


19 48 


42.7 


18 69 


15.18 


18 81 


15.28 


19.05 


15.48 


19 29 


16.69 


19 54 


42.8 


18.75 


15.23 


18 87 


15.33 


19 11 


15.53 


19 36 


15.74 


19 60 


42.9 


18.81 


15.28 


18 93 


15.38 


19.17 


15.58 


19.42 


15.79 


19.66 



XVIJ 



Table.— Continued. 



WINES 



219 
6 



21° C. 


22 


C. 


23° 


c. 


24° 


c. 


25 


c. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
BEADINO 


by 


hy 


by 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




IS. 47 


16 86 


IS. 67 


17.11 


13.87 


17.36 


14.0s 


17.59 


14.28 


38.0 


IS. 58 


16 92 


13.72 


17.17 


13.93 


17.41 


14.13 


17.66 


14.33 


38.1 


IS. 58 


16 99 


13.78 


17.23 


13.98 


17.47 


14-18 


17 72 


14.38 


38.2 


1S.6S 


17 05 


13.83 


17 30 


14-03 


17.64 


14.2s 


17.78 


14.43 


38.3 


IS. 68 


17.11 


13.88 


17.36 


14-08 


17.60 


14-29 


17.85 


14.49 


38.4 


1S.7S 


17.18 


13.93 


17.42 


14.14 


17.66 


14.34 


17 91 


14.54 


38.5 


IS. 79 


17 24 


13.98 


17.48 


14.19 


17.73 


14.39 


17 97 


14.59 


38.6 


IS. 84 


17.30 


14-04 


17 55 


14.24 


17.79 


14.44 


18.04 


14-64 


38.7 


IS. 89 


17 36 


14-09 


17.61 


14.29 


17 85 


14.49 


18.10 


14-70 


38.8 


IS. 94 


17.43 


14-14 


17.67 


14.34 


17.92 


14.55 


18 16 


14-75 


38.9 


IS. 99 


17 49 


14-19 


17 74 


14.40 


17.98 


14. 60 


18 23 


14. 80 


39.0 


14.05 


17 55 


14-24 


17.80 


14.45 


18 04 


14.65 


18 29 


14-85 


39.1 


14.10 


17.62 


14. SO 


17.86 


14.50 


18.11 


14.70 


18 35 


14-91 


39.2 


14.15 


17 68 


14-35 


17 92 


14.55 


18 17 


14.76 


18 42 


14-96 


39.3 


14.20 


17.74 


14-40 


17.99 


14. 60 


18 23 


14. 81 


18 48 


15.01 


39.4 


14.25 


17 81 


14-45 


18 05 


14.66 


18 30 


14.86 


18.54 


15.06 


39.5 


14. SO 


17 87 


14-50 


18 11 


14.71 


18 36 


14.91 


18 61 


15.12 


39.6 


14. SB 


17 93 


14-56 


18 18 


14.76 


18.42 


14.96 


18 67 


15.17 


39.7 


14.41 


17 99 


14-61 


18 24 


14. 81 


18.48 


15.02 


18 73 


15. S2 


39.8 


14.46 


18 06 


14-66 


18 30 


14.87 


18.55 


15.07 


18 80 


15.27 


39.9 


14.51 


18 12 


14-71 


18 36 


14.92 


18.61 


15.12 


18 86 


15.32 


40.0 


14-56 


18 18 


14-77 


18 43 


14-97 


18 67 


15.17 


18 92 


15.38 


40.1 


14-61 


18 24 


14-82 


18 49 


15.02 


18.74 


15.22 


18 99 


15.43 


40.2 


14-67 


18 30 


14-87 


18 55 


15.07 


18 80 


15.27 


19 06 


15.48 


40.3 


14-72 


18 37 


14-92 


18 61 


15.12 


18 86 


15.33 


19 11 


15.53 


40.4 


14-77 


18.43 


14-97 


18 68 


15.17 


18 92 


15.38 


19 18 


15.59 


40.6 


14-82 


18 49 


15. OS 


18.74 


15.23 


18 99 


15.43 


19 24 


15.64 


40.6 


14.87 


18 55 


15.08 


18 80 


15.28 


19 05 


15.48 


19 30 


15.69 


40.7 


14-92 


18 61 


15. IS 


18 86 


15.33 


19 11 


15.53 


19 37 


15.74 


40.8 


14-97 


18 68 


15.18 


18 93 


15.38 


19 18 


15.59 


19 43 


15.80 


40.9 


15. OS 


18.74 


15.23 


18.99 


15.4s 


19.24 


15.64 


19 49 


15.85 


41.0 


15.08 


18 80 


15.28 


19.05 


15.48 


19 30 


15.69 


19 56 


15.90 


41.1 


15. IS 


18 86 


15.33 


19.11 


15.53 


19 36 


15.74 


19.62 


15.95 


41.2 


15.18 


18 93 


15.38 


19 17 


15.58 


19.43 


15.79 


19 68 


16.01 


41.3 


15. 2S 


18 99 


15.43 


19.24 


15.64 


19.49 


16.84 


19 75 


16.06 


41.4 


15.28 


19 05 


15.48 


19 30 


15.69 


19.55 


15.90 


19 81 


16.11 


41.5 


15. SS 


19 11 


15.53 


19 36 


15.74 


19 61 


15.95 


19 87 


16.16 


41.6 


15. S8 


19 17 


15.58 


19.42 


15.79 


19.68 


16.00 


19.94 


16.21 


41.7 


15.4S 


19.23 


15.63 


19.48 


15.84 


19.74 


16.05 


20.00 


16.27 


41.8 


15.48 


19 29 


15.69 


19.66 


15.89 


19 80 


16.10 


20.06 


16.32 


41.9 


15.53 


19 36 


15.74 


19 61 


15.94 


19.86 


16.16 


20.13 


16.37 


42.0 


15.58 


19 42 


15.79 


19 67 


15.99 


19.93 


16.21 


20.19 


16. 42 


42.1 


15.6S 


19 48 


15.84 


19 73 


16.05 


19.99 


16.26 


20 26 


16.48 


42.2 


15.69 


19.54 


15.89 


19.80 


16.10 


20.05 


18.31 


20 31 


16.53 


42.3 


15.74 


19.60 


15.94 


19.86 


16.15 


20.11 


16.36 


20.38 


16.58 


42.4 


16.79 


19.66 


15.99 


19.92 


16.20 


20.18 


16. 41 


20.44 


16.63 


42.5 


15.84 


19.72 


16.04 


19.98 


16.25 


20.24 


16. 47 


20.50 


16.79 


42.6 


15.89 


19.79 


16.09 


20.04 


16.30 


20.30 


16.52 


20.67 


16.74 


42.7 


15.94 


19.85 


16.14 


20 10 


16.35 


20 36 


16.57 


20.63 


16.79 


42.8 


15.99 


19.91 


16.19 


20.17 


16. 41 


20.43 


16.62 


20.69 


16.84 


42.9 



220 



METHODS OF ANALYSIS 



[Chap. 



Table 17.— Alcohol 





17.5 


■c. 


18° 


C. 


19° 


C. 


20° 


C. 


21° C. 


SCALE 
READING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


43.0 


18 87 


15. S3 


18 99 


15.43 


19 23 


15.63 


19 48 


15.84 


19 72 


43.1 


18 93 


15.S8 


19 05 


15.48 


19,29 


15.68 


19.64 


15.89 


19,79 


43.2 


18 99 


15.4S 


19 11 


15.63 


19 36 


15.73 


19 60 


15.94 


19.86 


43.3 


19 05 


15.48 


19 17 


15.58 


19,41 


15.78 


19 66 


15.99 


19,91 


43.4 


19 11 


15.53 


19 23 


15.63 


19,47 


16.83 


19.72 


16.04 


19,97 


43.5 


19 17 


15.58 


19 29 


15.68 


19 63 


15.88 


19 79 


16.09 


20 03 


43.6 


19 23 


15.63 


19 36 


15.73 


19 59 


16.93 


19 86 


16.14 


20 09 


43.7 


19 29 


15.68 


19 41 


15.78 


19 66 


15.98 


19 91 


16.19 


20 16 


43.8 


19 35 


16.73 


19 47 


15.83 


19 72 


16.03 


19 97 


16.24 


20 21 


43.9 


19 40 


15.78 


19 53 


15.88 


19,78 


16.08 


20 03 


16.29 


20 27 


44.0 


19.46 


15.83 


19 59 


16.93 


19 84 


16.13 


20.09 


16.34 


20,34 


44.1 


19 62 


15.88 


19,66 


16.98 


19 90 


16.18 


20.16 


16.39 


20 40 


44.2 


19.68 


15.93 


19 71 


16.03 


19 96 


16.23 


20 21 


16. U 


20 46 


44.3 


19 64 


15.98 


19 77 


16.08 


20 02 


16.28 


20.27 


16.49 


20 62 


44.4 


19 70 


16.02 


19 83 


16.13 


20,08 


16.33 


20.33 


16.55 


20 68 


44.5 


19 76 


16.07 


19 89 


16.18 


20 14 


16.38 


20 39 


16.60 


20 64 


44.6 


19 82 


16.12 


19 96 


16.23 


20,20 


16.43 


20.46 


16.66 


20 70 


44.7 


19 88 


16.17 


20 01 


16.27 


20 26 


16.48 


20 62 


16.70 


20,76 


44.8 


19 94 


16.22 


20 07 


16.32 


20 32 


16.53 


20 68 


16.75 


20,82 


44.9 


20.00 


16.27 


20 12 


16.37 


20 38 


16.58 


20.64 


16.80 


20 88 


45.0 


20 06 


16.32 


20 18 


16.42 


20,44 


16.63 


20.70 


16.85 


20 96 


45.1 


20.12 


16.87 


20 24 


16.47 


20 60 


16.68 


20.76 


16.90 


21 01 


45.2 


20 18 


16.41 


20 30 


16.52 


20 66 


16.73 


20 82 


16.95 


21 07 


45.3 


20 24 


16.46 


20 36 


16.67 


20 62 


16.78 


20,88 


17.00 


21 13 


45.4 


20 29 


16.51 


20 42 


16.62 


20 68 


16.83 


20,94 


17.05 


21 19 


45.5 


20 36 


16.56 


20 48 


16.67 


20,74 


16.88 


21,00 


17.10 


21 26 


45.6 


20 41 


16.61 


20 64 


16.72 


20 80 


16.93 


21 06 


17.15 


21 31 


45.7 


20.47 


16.66 


20 60 


16.76 


20 86 


16.98 


21,12 


17.20 


21 37 


45.8 


20 63 


16.71 


20 66 


16.81 


20 92 


17.03 


21,18 


17.26 


21 43 


45.9 


20.69 


16.76 


20.72 


16.86 


20,98 


17.08 


21,24 


17.30 


21 49 


46.0 


20 66 


16.80 


20 78 


16.91 


21 04 


17.13 


21 30 


17.36 


21 64 


46.1 


20 71 


16.85 


20 83 


16.96 


21 10 


17.18 


21,36 


17.40 


21 60 


46.2 


20 76 


16.90 


20.89 


17.01 


21 16 


17.23 


21.42 


17.45 


21,66 


46.3 


20 82 


16.95 


20 96 


17.06 


21 22 


17.28 


21.48 


17.50 


21 72 


46.4 


20 88 


17.00 


21.01 


17.11 


21,28 


17.33 


21,64 


17.66 


21 78 


46.5 


20.94 


17.05 


21 07 


17.16 


21 34 


17.38 


21 60 


17.60 


21 84 


46.6 


21 00 


17.10 


21.13 


17.21 


21,40 


17.43 


21 66 


17.65 


21 90 


46.7 


21 06 


17.16 


21.19 


17.26 


21 46 


17.48 


21 72 


17.70 


21,96 


46.8 


21.12 


17.20 


21 26 


17.31 


21 62 


17.63 


21.78 


17.75 


22 02 


46.9 


21 18 


17.26 


21 31 


17.36 


21 68 


17.68 


21,84 


17.80 


22.09 


47.0 


21 24 


17.30 


21 37 


17.41 


21.64 


17.63 


21 90 


17.86 


22 16 


47.1 


21 30 


17.35 


21 43 


17.46 


21 70 


17.68 


21,96 


17.90 


22.21 


47.2 


21.36 


17.40 


21,49 


17.61 


21.76 


17.73 


22,02 


17.96 


22 27 


47.3 


21.42 


17.45 


21 66 


17.56 


21.82 


17.78 


22,08 


18.01 


22 33 


47.4 


21.48 


17.60 


21 61 


17.61 


21.88 


17.83 


22,16 


18.06 


22,39 


47.5 


21 64 


17.56 


21.67 


17.66 


21.94 


17.88 


22.21 


18.11 


22,46 


47.6 


21.60 


17.60 


21.73 


17.71 


22 00 


17.94 


22.27 


18.16 


22 61 


47.7 


21.66 


17.66 


21.79 


17.76 


22 06 


17.99 


22 33 


18.21 


22 68 


47.8 


21.72 


17.70 


21.86 


17.81 


22.12 


18.04 


22.39 


18.26 


22,64 


47.9 


21.78 


17.75 


21.91 


17.86 


22.18 


18.09 


22.46 


18.31 


22,70 



XVI] 



WINES 



221 



Table.— Continued. 



21° C. 


22° 


C. 


23° 


C. 


24° 


C. 


25° 


C. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
READING 


by 


by 


by 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




16.04 


19 97 


16.24 


20.23 


16.46 


20.49 


16.67 


20 75 


16.90 


43.0 


16.09 


20 03 


16.30 


20.29 


16.51 


20.56 


16.73 


20 82 


16.96 


43.1 


16.14 


20 09 


16.35 


20.35 


16.56 


20 61 


16.78 


20 88 


17.00 


43.2 


16.19 


20 15 


16.40 


20.41 


16.61 


20 68 


16.83 


20 94 


17.05 


43.3 


16. U 


20.21 


16.45 


20.47 


16.66 


20.74 


16.88 


21 01 


17.10 


43.4 


16.29 


20 28 


16.50 


20 53 


16.71 


20 80 


16.93 


21 07 


17.16 


43.5 


16.34 


20 34 


16.55 


20 60 


16.76 


20 86 


16.98 


21 13 


17.21 


43.6 


16.40 


20 40 


16.60 


20 66 


16.82 


20 93 


17.04 


21 19 


17.26 


43.7 


16.45 


20 46 


16.65 


20.72 


16.87 


20 99 


17.09 


21 25 


17.31 


43.8 


16.50 


20 52 


16.70 


20 78 


16.92 


21 06 


17.14 


21 32 


17.36 


43.9 


16.55 


20 58 


16.76 


20 84 


16.97 


21 11 


17.19 


21 38 


17.41 


44.0 


16.60 


20 64 


16.81 


20 90 


17.02 


21 17 


17.24 


21.44 


17.47 


44.1 


16.65 


20 71 


16.86 


20 96 


17.07 


21 23 


17.29 


21 50 


17.62 


44.2 


16.70 


20 77 


16.91 


21 02 


17.12 


21 30 


17.35 


21 57 


17.57 


44.3 


16.75 


20 83 


16.96 


21 09 


17.17 


21 36 


17.40 


21 63 


17.62 


44.4 


16.80 


20 89 


17.01 


21 15 


17.22 


21 42 


17.45 


21 69 


17.67 


44 5 


16.85 


20 95 


17.06 


21 21 


17.28 


21.48 


17.50 


21 76 


17.73 


44.6 


16.90 


21 01 


17.11 


21 27 


17.33 


21 54 


17.55 


21 81 


17.78 


44.7 


16.95 


21 07 


17.16 


21 33 


17.38 


21 60 


17.60 


21 88 


17.83 


44.8 


17.01 


21 13 


17.21 


21 39 


17.43 


21 67 


17.65 


21 94 


17.88 


44.9 


17.06 


21 19 


17.26 


21 45 


17.48 


21 73 


17.71 


22 00 


17.93 


45.0 


17.11 


21 25 


17.31 


21 52 


17.53 


21 79 


17.76 


22 06 


17.98 


45.1 


17.16 


21 31 


17.36 


21 58 


17.58 


21 85 


17.81 


22 13 


18.04 


45.2 


17.21 


21 37 


17.41 


21 64 


17.63 


21 91 


17.86 


22.19 


18.09 


45.3 


17.26 


21 43 


17.46 


21 70 


17.68 


21 98 


17.91 


22 26 


18.14 


45.4 


17.31 


21 49 


17.51 


21 76 


17.73 


22 04 


17.96 


22 32 


18.20 


45.5 


17.36 


21 56 


17.56 


21 82 


17.79 


22 10 


18.02 


22 38 


18.25 


45.6 


17.41 


21 61 


17.61 


21 88 


17.84 


22 16 


18.07 


22.45 


18.30 


45.7 


17.46 


21 67 


17.66 


21 94 


17.89 


22.23 


18.12 


22 51 


18.36 


45.8 


17.51 


21.73 


17.71 


22 01 


17.94 


22 29 


18.17 


22 57 


18.41 


45.9 


17.56 


21 79 


17.76 


22 07 


17.99 


22 35 


18.23 


22 64 


18.47 


46.0 


17.61 


21.85 


17.81 


22.13 


18.04 


22.42 


18.28 


22 70 


18.62 


46.1 


17.66 


21 91 


17.86 


22.19 


18.09 


22 48 


18.33 


22 76 


18.67 


46.2 


17.71 


21 97 


17.91 


22 26 


18.15 


22.54 


18.39 


22 83 


18.63 


46.3 


17.76 


22 03 


17.96 


22 32 


18.20 


22 61 


18.44 


22.89 


18.68 


46.4 


17.81 


22 09 


18.01 


22 38 


18.25 


22.67 


18.49 


22 96 


18.73 


46.5 


17.86 


22 16 


18.06 


22.44 


18.30 


22.73 


18.55 


23 02 


18.79 


46.6 


17.91 


22 22 


18.11 


22 51 


18.36 


22 80 


18.60 


23.08 


18.84 


46.7 


17.96 


22 28 


18.17 


22 57 


18.41 


22.86 


18.66 


23 16 


18.90 


46.8 


18.01 


22 34 


18.22 


22 63 


18.46 


22 92 


18.70 


23.21 


18.96 


46.9 


18.06 


22.41 


18.27 


22.69 


18.61 


22.99 


18.76 


23.28 


19.00 


47.0 


18.11 


22.47 


18.32 


22.76 


18.57 


23 05 


18.81 


23 34 


19.06 


47.1 


18.16 


22 63 


18.38 


22.82 


18.62 


23.12 


18.86 


23.41 


19.11 


47.2 


18.21 


22 69 


18.43 


22.88 


18.67 


23.18 


18.92 


23.47 


19.16 


47.3 


18.26 


22.66 


18.48 


22 94 


18.72 


23.24 


18.97 


23.64 


19.22 


47.4 


18.31 


22.72 


18.53 


23.01 


18.78 


23.31 


19.02 


23 60 


19.27 


47.5 


18.36 


22.78 


18.58 


23.07 


18.83 


23 37 


19.08 


23 67 


19.33 


47.6 


18.42 


22.84 


18.64 


23.13 


18.88 


23.44 


19.13 


23 73 


19.38 


47.7 


18.47 


22.91 


18.69 


23.20 


18.93 


23 50 


19.18 


23 80 


19.43 


47.8 


18.52 


22.97 


18.74 


23 26 


18.99 


23.56 


19.24 


23.86 


19.49 


47.9 



222 
6 



METHODS OF ANALYSIS 



[Chap. 



Table 17. — Alcohol 





17.5" 


C. 


18° 


C. 


19° 


C. 


20° 


C. 


21° C. 


SCALE 
READINQ 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


48.0 


21 84 


17.80 


21.97 


17.91 


22.24 


18.14 


22 61 


18.36 


22.76 


48.1 


21 90 


17.85 


22.03 


17.96 


22 30 


18.19 


22.67 


18.41 


22.82 


48.2 


21 96 


17.90 


22.09 


18.01 


22.36 


18.24 


22.63 


18.46 


22.88 


48.3 


22.02 


17.95 


22.16 


18.06 


22.42 


18.29 


22 69 


18.51 


22.94 


48.4 


22.08 


18.00 


22.21 


18.11 


22.48 


18.34 


22.75 


18.66 


23 01 


48.5 


22 14 


18.05 


22 27 


18.16 


22.64 


18.39 


22 81 


18.61 


23 07 


48.6 


22 20 


18.10 


22 33 


18.21 


22 60 


18.44 


22.87 


18.66 


23.13 


48.7 


22 26 


18.15 


22.39 


18.26 


22.66 


18.49 


22 93 


18.71 


23.19 


48.8 


22 32 


18.20 


22.45 


18. SI 


22.72 


18.54 


22.99 


18.76 


23.26 


48.9 


22 38 


18.25 


22.61 


18.36 


22.78 


18.69 


23.06 


18.81 


23.32 


49.0 


22.44 


18.30 


22 67 


18.41 


22.84 


18.64 


23.12 


18.86 


23.38 


49.1 


22.50 


18. S5 


22.63 


18.46 


22.90 


18.69 


23.18 


18.91 


23.44 


49.2 


22.66 


18.40 


22 69 


18.61 


22.96 


18.74 


23 24 


18.96 


23.61 


49.3 


22.62 


18.45 


22.76 


18.66 


23.02 


18.79 


23 30 


19.02 


23.67 


49.4 


22.68 


18.60 


22.81 


18.61 


23.08 


18.84 


23.36 


19.07 


23 63 


49.5 


22.74 


18.55 


22.87 


18.66 


23.16 


18.89 


23.42 


19.12 


23.69 


49.6 


22.80 


18.60 


22.93 


18.71 


23.21 


18.94 


23.48 


19.17 


23.76 


49.7 


22.86 


18.65 


22.99 


18.76 


23.27 


18.99 


23 66 


19.22 


23.82 


49.8 


22 92 


18.70 


23 06 


18.81 


23 33 


19.04 


23.61 


19.27 


23.88 


49.9 


22 98 


18.75 


23.11 


18.86 


23 39 


19.09 


23.67 


19.32 


23.94 


50.0 


23.04 


18.80 


23.17 


18.91 


23.46 


19.14 


23.73 


19.38 


24.01 


50.1 


23.10 


18.85 


23 23 


18.96 


23 61 


19.19 


23.79 


19.43 


24.07 


50.2 


23.16 


18.90 


23.30 


19.02 


23 67 


19.24 


23 86 


19.48 


24.13 


50.3 


23.22 


18.95 


23 36 


19.07 


23 63 


19.29 


23.91 


19.63 


24.19 


50.4 


23.28 


19.00 


23.42 


19.12 


23.69 


19.35 


23.98 


19.58 


24.26 


50.5 


23 34 


19.05 


23.48 


19.17 


23.76 


19.40 


24.04 


19.63 


24.32 


50.6 


23 40 


19.10 


23.64 


19.22 


23 81 


19.45 


24 10 


19.69 


24.38 


50.7 


23 46 


19.16 


23.60 


19.27 


23 87 


19.50 


24.16 


19.74 


24.46 


50.8 


23 61 


19.20 


23.66 


19.32 


23.93 


19.65 


24 22 


19.79 


24.61 


50.9 


23.67 


19.26 


23.72 


19. S7 


23 99 


19.60 


24 28 


19.84 


24.67 


61.0 


23.63 


19. SO 


23 78 


19.42 


24 06 


19.65 


24 36 


19.89 


24.64 


51.1 


23 69 


19.S5 


23 84 


19.47 


24 12 


19.70 


24.41 


19.94 


24.70 


51.2 


23 76 


19.40 


23.90 


19.62 


24.18 


19.75 


24.47 


20.00 


24.76 


51.3 


23.81 


19.45 


23 96 


19.67 


24.24 


19.80 


24.63 


20.06 


24.82 


51.4 


23.87 


19.60 


24.02 


19.62 


24.30 


19.85 


24.69 


20.10 


24.89 


51.5 


23.93 


19.56 


24.08 


19.67 


24.36 


19.90 


24.66 


20.16 


24.96 


51.6 


23.99 


19.60 


24.14 


19.72 


24.42 


19.95 


24.72 


20.20 


26.01 


51.7 


24.06 


19.65 


24.20 


19.77 


24.48 


20.01 


24.78 


20.26 


26.07 


51.8 


24.11 


19.70 


24.26 


19.82 


24.54 


20.08 


24.84 


20.31 


26.14 


51.9 


24.17 


19.75 


24.32 


19.87 


24.60 


20.11 


24.90 


20.36 


26.20 


52.0 


24.23 


19.80 


24.38 


19.92 


24.66 


20.16 


24.96 


20.41 


25.27 


52.1 


24.30 


19.85 


24.44 


19.97 


24.73 


20.21 


25.03 


20.46 


26.33 


52.2 


24.36 


19.90 


24.60 


20.02 


24.79 


20.26 


25.09 


20.52 


26.39 


52.3 


24.42 


19.95 


24.56 


20.07 


24.85 


20.31 


25.16 


20.57 


26.46 


52.4 


24.48 


20.00 


24.62 


20.12 


24.91 


20.37 


26.21 


20.62 


25.62 


52.5 


24.54 


20.05 


24.68 


20.17 


24.97 


20.42 


26.28 


20.67 


25.68 


52.6 


24.60 


20.10 


24.74 


20.22 


25.03 


20.47 


25.34 


20.72 


25.66 


52.7 


24.66 


20.15 


24.80 


20.28 


26.09 


20.52 


26.40 


20.78 


26.71 


52.8 


24.72 


20.20 


24.86 


20. SS 


26.15 


20.67 


26.46 


20.83 


25.77 


52.9 


24.78 


20.25 


24.92 


20.38 


26.22 


20.62 


26.63 


20.88 


26.84 



XVI] 



Table. — Continued. 



WINES 



223 
6 



21° C. 


22° 


C. 


23° 


c. 


24° 


c. 


25° C. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
READINO 


by 


by 


by 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




18.57 


23 03 


18.79 


23.32 


19.04 


23.63 


19.29 


23 93 


19.54 


48.0 


18.62 


23.09 


18.84 


23.39 


19.09 


23.69 


19.34 


23.99 


19.60 


48.1 


18.67 


23.16 


18.90 


23.45 


19.14 


23.76 


19.40 


24.06 


19.65 


48.2 


18.72 


23.22 


18.95 


23 52 


19.20 


23.83 


19.45 


24.13 


19.71 


48.3 


18.77 


23.28 


19.00 


23 58 


19.25 


23.89 


19.50 


24.19 


19.76 


48.4 


18.83 


23 35 


19.06 


23.64 


19.31 


23.96 


19.56 


24.26 


19.82 


48.5 


18.88 


23.41 


19.11 


23.71 


19.36 


24.02 


19.61 


24,32 


19.87 


48.6 


18.93 


23.47 


19.16 


23.77 


19.41 


24.08 


19.67 


24.39 


19.92 


48.7 


18.98 


23.64 


19.21 


23.83 


19.47 


24.14 


19.72 


24 45 


19.98 


48.8 


19.03 


23.60 


19.27 


23 90 


19.52 


24.21 


19.77 


24.52 


20.03 


48.9 


19.08 


23 66 


19.32 


23 96 


19.57 


24.27 


19.83 


24.59 


20.09 


49.0 


19.14 


23 73 


19.37 


24.03 


19.63 


24.34 


19.88 


24.65 


20.15 


49.1 


19.19 


23 79 


19.43 


24.09 


19.68 


24.40 


19.94 


24.72 


20.20 


49.2 


19.24- 


23 85 


19.48 


24.15 


19.73 


24.47 


19.99 


24.78 


20.26 


49.3 


19.29 


23.92 


19.54 


24.22 


19.79 


24.53 


20.04 


24.85 


20.31 


49.4 


19.35 


23 98 


19.59 


24.28 


19.84 


24.60 


20.10 


24.91 


20.37 


49.5 


19.40 


24.04 


19.64 


24.35 


19.89 


24.66 


20.15 


24.98 


20.42 


49.6 


19.45 


24.11 


19.70 


24.41 


19.95 


24.73 


20.21 


25.05 


20.48 


49.7 


19.51 


24.17 


19.75 


24.48 


20.00 


24.79 


20.27 


25.11 


20.54 


49.8 


19.56 


24.24 


19.80 


24.54 


20.05 


24.86 


20.32 


25.18 


20.59 


49.9 


19.61 


24.30 


19.86 


24.61 


20.11 


24.92 


20.38 


25.26 


20.65 


50.0 


19.66 


24.37 


19.91 


24.67 


20.16 


24 99 


20.43 


25.31 


20.70 


50.1 


19.72 


24.43 


19.96 


24.74 


20.22 


25.05 


20.49 


25.38 


20.76 


50.2 


19.77 


24.49 


20.02 


24.80 


20.27 


25.12 


20.54 


25.45 


20.82 


50.3 


19.82 


24.56 


20.07 


24.86 


20.33 


25.18 


20.60 


25.51 


20.87 


50.4 


19.87 


24.62 


20.12 


24.93 


20.38 


25.25 


20.65 


25.58 


20.93 


50.5 


19.93 


24.69 


20.18 


24.99 


20.44 


25.32 


20.71 


25 65 


20.98 


50.6 


19.98 


24.75 


20.23 


25.06 


20.49 


25 38 


20.76 


25.71 


21.04 


50.7 


20.03 


24.81 


20.29 


25.12 


20.55 


25.45 


20.82 


25.78 


21.10 


50.8 


20.08 


24.88 


20.34 


25.19 


20.60 


25.51 


20.87 


25.86 


21.15 


50.9 


20.14 


24.94 


20.39 


25.25 


20.66 


25.68 


20.93 


25.91 


21.21 


51.0 


20.19 


25.01 


20.45 


25.32 


20.71 


25.64 


20.98 


25.98 


21.27 


51.1 


20.24 


25 07 


20.50 


25.38 


20.77 


25.71 


21.04 


26 05 


21.32 


51.2 


20.30 


25 13 


20.55 


25.45 


20.82 


25.78 


21.09 


26 11 


21.38 


51.3 


20.35 


25.20 


20.61 


25.51 


20.87 


25.84 


21.15 


26.18 


21.44 


51.4 


20.40 


25.26 


20.66 


25.58 


20.93 


25 91 


21.21 


26.25 


21.49 


51.5 


20.46 


25.33 


20.72 


25.64 


20.98 


25.97 


21.26 


26.32 


21.55 


51.6 


20.51 


25.39 


20.77 


25.71 


21.04 


26 04 


21.32 


26.39 


21.61 


51.7 


20.56 


25.46 


20.82 


25.77 


21.09 


26.11 


21.37 


26.45 


21.66 


51.8 


20.61 


25.52 


20.88 


25.84 


21.15 


26.17 


21.43 


26.52 


21.72 


51.9 


20.67 


25.58 


20.93 


25.90 


21.20 


26.24 


21.49 


26.59 


21.78 


52.0 


20.72 


25.65 


20.98 


25.97 


21.26 


26.31 


21.54 


26.66 


21.83 


52.1 


20.77 


25.71 


21.04 


26.03 


21.31 


26.37 


21.60 


26.72 


21.89 


52.2 


20.83 


25.78 


21.09 


26.10 


21.37 


26.44 


21.65 


26.79 


21.95 


52.3 


20.88 


25.84 


21.15 


26 16 


21.42 


26.51 


21.71 


26.86 


22.01 


52.4 


20.93 


25.90 


21.20 


26.23 


21.48 


26.57 


21.77 


26.93 


22.06 


52.5 


20.98 


25.97 


21.26 


26.29 


21.53 


26.64 


21.82 


26.99 


22.12 


52.6 


21.04 


26.03 


21.31 


26.36 


21.59 


26.71 


21.88 


27.06 


22.18 


52.7 


21.09 


26.10 


21.36 


26.42 


21.64 


26.77 


21.93 


27.13 


22.24 


52.8 


21.15 


26.16 


21.42 


26.49 


21.70 


26.84 


21.99 


27.20 


22.29 


52.9 



224 
6 



METHODS OF ANALYSIS 



[Chap. 



Table 17. — Alcohol 





17.5 


°C. 


18 


0. 


19 


c. 


20 


C. 


21° C. 


SCALE 
HEADING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


53.0 


24.84 


20.80 


24.98 


20.43 


26.28 


20.68 


25.69 


20.93 


25.90 


53.1 


24 90 


20.36 


26 04 


20.48 


25.34 


20.73 


25 65 


20.98 


25.96 


53.2 


24.96 


20. U 


26.10 


20.58 


26.40 


20.78 


26.71 


21.04 


26.03 


53.3 


25.02 


20.1^6 


26.16 


20.68 


25.46 


20.88 


26.77 


21.09 


26.09 


53.4 


25.08 


20.51 


26.23 


20.63 


25.52 


20.88 


26.84 


21.14 


26.15 


53.5 


25.14 


20.56 


25 29 


20.68 


26.59 


20.98 


25.90 


21.20 


26.22 


53.6 


25.20 


20.61 


25 36 


20.74 


25.66 


20.98 


25.96 


21.25 


26 28 


53.7 


25 26 


20.66 


26.41 


20.79 


26.71 


21.04 


26.03 


21.80 


26.35 


53.8 


25.32 


20.71 


26.47 


20.84 


26.77 


21.09 


26.09 


21.36 


26.41 


53.9 


25.38 


20.76 


26.63 


20.89 


26.83 


21.14 


26.15 


21.41 


26.47 


54.0 


25 44 


20.81 


26.69 


20.94 


26 90 


21.19 


26 22 


21.47 


26.54 


54.1 


25 50 


20.86 


25 65 


20.99 


26.96 


21.25 


26 28 


21.52 


26.60 


54.2 


25 56 


20.91 


25.71 


21.04 


26.02 


21.30 


26.34 


21.67 


26.67 


54.3 


25 62 


20.96 


26.77 


21.09 


26 08 


21.35 


26.41 


21.63 


26.73 


54.4 


25.68 


21.02 


26.84 


21.14 


26.14 


21.40 


26.47 


21.68 


26.79 


54.5 


25.75 


21.07 


26.90 


21.20 


26.20 


21.46 


26.53 


21.73 


26.86 


54.6 


25.81 


21.12 


25 96 


21.25 


26 27 


21.51 


26 59 


21.79 


26.92 


54.7 


25.87 


21.17 


26 02 


21.80 


26 33 


21.56 


26.66 


21.84 


26 99 


54.8 


26.93 


21.22 


26.08 


21.85 


26 39 


21.62 


26.72 


21.90 


27.05 


54.9 


25.99 


21.27 


26.14 


21.40 


26.45 


21.67 


26.78 


21.95 


27.11 


55.0 


26.06 


21.32 


26.20 


21.45 


26.52 


21.72 


26,85 


22.00 


27.18 


55.1 


26.11 


21.87 


26.26 


21.61 


26 68 


21.77 


26.91 


22.05 


27.24 


55.2 


26.17 


21.43 


26.32 


21.66 


26 64 


21.88 


26.97 


22.11 


27.31 


55.3 


26 23 


21.48 


26 38 


21.61 


26.70 


21.88 


27.04 


22.16 


27.37 


55.4 


26.29 


21.53 


26.46 


21.66 


26.76 


21.93 


27.10 


22.21 


27.43 


65.5 


26 35 


21.58 


26.61 


21.71 


26.83 


21.98 


27.16 


22.26 


27.49 


55.6 


26.41 


21.63 


26.67 


21.76 


26 89 


22.04 


27.23 


22.82 


27.55 


55.7 


26.47 


21.68 


26 63 


21.81 


26 95 


22.09 


27 29 


22.37 


27.62 


55.8 


26.53 


21.73 


26 69 


21.87 


27 01 


22.14 


27.35 


22.42 


27.69 


55.9 


26.59 


21.79 


26.76 


21.92 


27 07 


22.19 


27.41 


22.48 


27.76 


56.0 


26.66 


21.84 


26.81 


21.97 


27.14 


22.24 


27.48 


22.53 


27 82 


56.1 


26 72 


21.89 


26.87 


22.02 


27.20 


22.30 


27.54 


22.68 


27,88 


56.2 


26 78 


21.94 


26.93 


22.07 


27 26 


22.35 


27.60 


22.64 


27.94 


56.3 


26 84 


21.99 


26.99 


22.12 


27 32 


22.40 


27.66 


22.69 


28 01 


56.4 


26.90 


22.04 


27.06 


22.18 


27.38 


22.45 


27.73 


22.74 


28.07 


56.5 


26 96 


22.09 


27.12 


22.23 


27.44 


22.50 


27.79 


22.79 


28.14 


56.6 


27.02 


22.14 


27.18 


22.28 


27.51 


22.66 


27.85 


22.85 


28 20 


56.7 


27.08 


22.19 


27.24 


22.33 


27.67 


22.61 


27.91 


22.90 


28.26 


56.8 


27 14 


22.25 


27.30 


22.38 


27.63 


22.66 


27.98 


22.95 


28.33 


56.9 


27.20 


22.30 


27.36 


22.43 


27.69 


22.71 


28.04 


23.01 


28.39 


57.0 


27.26 


22.35 


27.42 


22.48 


27.76 


22.77 


28.10 


23.06 


28.46 


57.1 


27.32 


22.40 


27.48 


22.54 


27 81 


22.82 


28.16 


23.11 


28.62 


57.2 


27.38 


22.45 


27.64 


22.69 


27.88 


22 .87 


28.23 


23.17 


28 59 


57.3 


27.44 


22.60 


27 60 


22.64 


27.94 


22.92 


28.29 


23.22 


28.65 


57.4 


27 50 


22.55 


27.66 


22.69 


28 00 


22.97 


28 36 


23.27 


28.72 


57.5 


27.56 


22.61 


27.73 


22.74 


28 06 


23.03 


28.42 


23.33 


28.78 


57.6 


27.62 


22.66 


27.79 


22.79 


28.13 


23.08 


28,48 


23.38 


28.85 


57.7 


27.68 


22.71 


27 86 


22.85 


28.19 


23.18 


28,54 


23.43 


28.91 


57.8 


27.75 


22.76 


27 91 


22.90 


28.25 


23.19 


28,60 


23.49 


28.97 


57.9 


27.81 


22.81 


27.97 


22.95 


28.31 


23.24 


28.67 


23.54 


29.04 



A^ 


^i-i 








WINES 








225 


Table- 


-Continued. 














6 


21° C. 


22 


'C. 


23 


■c. 


24 


'C. 


25 


'C. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCAXE 
READING 


by 


by 


by. 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




21.20 


26 23 


21.47 


26.56 


21.75 


26.91 


22.05 


27.27 


22.35 


53.0 


21.25 


26.29 


21.53 


26.62 


21.81 


26.97 


22.10 


27.33 


22.41 


53.1 


21. SI 


26 35 


21.58 


26 69 


21.86 


27.04 


22.16 


27.40 


22.47 


53.2 


21.36 


26 42 


21.64 


26.75 


21.92 


27.11 


22.22 


27.47 


22.52 


53.3 


21.42 


26.48 


21.69 


26.82 


21.97 


27.17 


22.27 


27.54 


22.58 


53.4 


21.47 


26.55 


21.74 


26.88 


22.03 


27.24 


22.33 


27.61 


22.64 


53.5 


21.52 


26 61 


21.80 


26.95 


22.08 


27.31 


22.39 


27.67 


22.70 


53.6 


21.58 


26 68 


21.85 


27.01 


22.14 


27.38 


22.44 


27.74 


22.75 


53.7 


21.63 


26.74 


21.91 


27.08 


22.20 


27.44 


22.50 


27.81 


22.81 


53.8 


21.69 


26.81 


21.96 


27.15 


22.25 


27.51 


22.56 


27 88 


22.87 


53.9 


21.74 


26 87 


22.02 


27.21 


22.31 


27.58 


22.61 


27.95 


22.93 


54.0 


21.79 


26 94 


22.07 


27 28 


22.37 


27.64 


22.67 


28 01 


22.98 


54.1 


21.85 


27.00 


22.13 


27 35 


22.42 


27 71 


22.73 


28 08 


23.04 


54.2 


21.90 


27.07 


22.18 


27.41 


22.48 


27.78 


22.78 


28.15 


23.10 


54.3 


21.96 


27.13 


22.24 


27.48 


22.53 


27 85 


22.84 


28.22 


23.16 


54.4 


22.01 


27.20 


22.29 


27.55 


22.59 


27.91 


22.90 


28 29 


23.22 


54.5 


22.06 


27 26 


22.35 


27.61 


22.65 


27.98 


22.95 


28.36 


23.27 


54.6 


22.12 


27 33 


22.40 


27.68 


22.70 


28.05 


23.01 


28 43 


23.33 


54.7 


22.17 


27 39 


22.46 


27.75 


22.76 


28.11 


23.07 


28.49 


23.39 


54.8 


22.23 


27 46 


22.51 


27 81 


22.81 


28.18 


23.13 


28.56 


23.45 


54.9 


22.28 


27 52 


22.57 


27.88 


22.87 


28.25 


23.18 


28 63 


23.51 


55.0 


22.33 


27 59 


22.63 


27.95 


22.93 


28 32 


23.24 


28 70 


23.56 


55.1 


22.39 


27.65 


22.68 


28 01 


22.98 


28.38 


23.30 


28.77 


23.62 


55.2 


22.44 


27.72 


22.74 


28 08 


23.04 


28.45 


23.35 


28.84 


23.68 


55.3 


22.49 


27.78 


22.79 


28.15 


23.10 


28.52 


23.41 


28.90 


23.74 


55.4 


22.55 


27.85 


22.85 


28 21 


23.15 


28.58 


23.47 


28 97 


23.80 


55.5 


22.60 


27.92 


22.90 


28.28 


23.21 


28.65 


23.53 


29 04 


23.86 


55.6 


22.66 


27 98 


22.96 


28.34 


23.26 


28.72 


23.58 


29.11 


23.91 


55.7 


22.71 


28.05 


23.01 


28.41 


23.32 


28.78 


23.64 


29.18 


23.97 


55.8 


22.76 


28.11 


23.07 


28.48 


23.38 


28.85 


23.70 


29.24 


24.03 


55.9 


22.82 


28 18 


23.12 


28.54 


23.43 


28.92 


23.75 


29 31 


24-09 


56.0 


22.87 


28.24 


23.18 


28.61 


23.49 


28 99 


23.81 


29.38 


24.14 


56.1 


22.92 


28 31 


23.23 


28.68 


23.54 


29.05 


23.87 


29 45 


24.20 


56.2 


22.98 


28.37 


23.29 


28.74 


23.60 


29.12 


23.93 


29 52 


24.26 


56.3 


23.03 


28 44 


23.34 


28.81 


23.66 


29.19 


23.98 


29.58 


24.32 


56.4 


23.09 


28.50 


23.40 


28 87 


23.71 


29 26 


24.04 


29.65 


24.38 


56.5 


23.14 


28 56 


23.45 


28.94 


23.77 


29 32 


24.10 


29.72 


24.43 


56.6 


23.20 


28 63 


23.51 


29.01 


23.83 


29.39 


24.15 


29.79 


24.49 


56.7 


23.25 


28.69 


23.56 


29.07 


23.88 


29.46 


24.21 


29 86 


24.55 


56.8 


23.31 


28.76 


23.62 


29.14 


23.94 


29.53 


24.27 


29.93 


24. 61 


56.9 


23.36 


28 82 


23.67 


29.20 


23.99 


29.59 


24.32 


29.99 


24.66 


57.0 


23.42 


28 89 


23.73 


29.27 


24.05 


29.66 


24.38 


30.06 


24.72 


57.1 


23.47 


28.95 


23.78 


29.34 


24.11 


29.73 


u.u 


30 13 


24 J 8 


55.2 


23.52 


29 02 


23.84 


29.40 


24. 16 


29.80 


24.49 


30 20 


24.84 


55.3 


23.58 


29.08 


23.90 


29.47 


24.22 


29.86 


24.55 


30.27 


24.90 


57.4 


23.63 


29.15 


23.95 


29.53 


24.27 


29 93 


24. 61 


30 34 


24.95 


57.5 


23.69 


29.21 


24.01 


29.60 


24.33 


30.00 


24.66 


30.41 


25.01 


57.6 


23.74 


29.28 


24. 06 


29.66 


24.39 


30.07 


24.72 


30.48 


25.07 


57.7 


23.80 


29.34 


24.12 


29.73 


H.44 


30.14 


24.78 


30.55 


25.13 


57.8 


23.85 


29.41 


24.17 


29.80 


24.50 


30.20 


24.83 


30.62 


25.19 


57.9 



226 
6 



METHODS OF ANALYSIS 



[Chap. 



Table 17.— Alcohol 





17.5 


"C. 


18 


'C. 


19 


c. 


20 


C. 


21° C. 


SCA.LE 
READING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


58.0 


27 87 


22.86 


28.03 


28.00 


28.38 


28.29 


28.73 


28.59 


29.10 


58.1 


27.93 


22.91 


28.09 


28.05 


28.44 


23.34 


28.79 


23.65 


29.17 


58.2 


27.99 


22.96 


28.15 


28.10 


28.50 


23.40 


28.86 


28.70 


29.23 


58.3 


28.05 


28.02 


28.21 


28.16 


28 66 


28.45 


28.92 


23.75 


29.29 


58.4 


28.11 


23.07 


28.28 


28.21 


28.62 


23.50 


28 98 


23.81 


29.36 


58.5 


28.17 


23.12 


28.34 


23.26 


28.69 


23 56 


29.04 


23.86 


29.42 


58.6 


28 23 


23.17 


28.40 


23.31 


28 75 


28.61 


29.11 


28.91 


29.48 


58.7 


28.29 


23.22 


28.46 


23.86 


28 81 


23.66 


29.17 


23.97 


29.65 


58.8 


28 35 


28.27 


28 52 


28.41 


28 88 


23.71 


29 23 


24.02 


29,61 


58.9 


28.41 


28.82 


28.58 


28.47 


28.94 


23.77 


29.30 


24. 08 


29.68 


59.0 


28 47 


23.37 


28 64 


23.52 


29.00 


23.82 


29 36 


24.13 


29.74 


59.1 


28 53 


23.43 


28.71 


23.57 


29 06 


28.87 


29.42 


24. 18 


29.80 


59.2 


28 59 


23.48 


28.77 


23.62 


29.12 


28.98 


29.49 


24.24 


29.87 


59.3 


28.65 


23.53 


28 83 


23.67 


29.19 


23.98 


29 55 


24.29 


29 93 


59.4 


28.71 


28.58 


28.89 


23.78 


29.25 


24.03 


29 61 


24.34 


29.99 


59.5 


28.78 


23.63 


28.95 


23.78 


29.31 


24. 08 


29.68 


24.40 


30.06 


59.6 


28 84 


28.68 


29.01 


28.83 


29 37 


24.14 


29.74 


24.45 


30 13 


59.7 


28 90 


28.73 


29.07 


23.88 


29 43 


24.19 


29 80 


24.50 


30 19 


59.8 


28 96 


23.79 


29 13 


28.93 


29 60 


24.24 


29.87 


24.56 


30 26 


59.9 


29.02 


23.84 


29.20 


23.98 


29 56 


24. 80 


29.93 


24. 61 


30.32 


60.0 


29.08 


23.89 


29 26 


24.04 


29 62 


24.35 


29.99 


24.67 


30.39 


60.1 


29.14 


23.94 


29.32 


24.09 


29.68 


24.40 


30.06 


24.72 


30.46 


60.2 


29.20 


28.99 


29 38 


24.14 


29.74 


24.46 


30.12 


24.77 


30.62 


60.3 


29.26 


24.04 


29.44 


24.19 


29 81 


24.51 


30.19 


24.88 


30 59 


60.4 


29 32 


24.10 


29.50 


24.25 


29.87 


24-56 


30.25 


24.88 


30.65 


60.5 


29 38 


24.15 


29 56 


24. SO 


29.93 


2 4. 61 


30 32 


24.94 


30.72 


60.6 


29 45 


24.20 


29 63 


24.85 


29.99 


24.67 


30 38 


24.99 


30 78 


60.7 


29 51 


24.25 


29 69 


24.40 


30.06 


24.72 


30.45 


25.04 


30 85 


60.8 


29.57 


24.80 


29.75 


24.46 


30.12 


24.77 


30 51 


25.10 


30.91 


60.9 


29.63 


24.85 


29.81 


24.51 


30.18 


24.83 


30 57 


25.16 


30 98 


61.0 


29 69 


24.41 


29 87 


24.56 


30 25 


24.88 


30.64 


25.21 


31 06 


61.1 


29.75 


24.46 


29 93 


24. 61 


30.31 


24.93 


30 70 


25.27 


31 11 


61.2 


29.81 


24.61 


29.99 


24.66 


30 38 


24.98 


30.77 


25.32 


31.18 


61.3 


29.87 


24.56 


30 06 


24.72 


30.44 


25.04 


30.83 


25.88 


31.25 


61.4 


29.93 


24.61 


30.12 


24.77 


30.50 


25.09 


30 90 


25.44 


31.32 


61.5 


29.99 


24.67 


30.18 


24.82 


30 57 


25.15 


30.96 


25.49 


31 39 


61.6 


30.06 


24.72 


30 25 


24.87 


30.63 


25.20 


31 03 


25.55 


31.46 


61.7 


30.12 


24.77 


30 31 


24.93 


30.69 


25.26 


31 09 


25.60 


31 52 


61.8 


30.18 


24.82 


30 37 


24.98 


30.76 


25.81 


31.16 


25.66 


31 59 


61.9 


30.25 


24.88 


30.44 


25.03 


30.82 


25.37 


31.23 


25.71 


31.66 


62.0 


30.31 


24.93 


30.50 


25.09 


30 89 


25.43 


31.29 


25.77 


31 72 


62.1 


30.37 


24.98 


30.56 


25.14 


30.95 


25.48 


31.36 


25.83 


31.79 


62.2 


30 43 


2^.03 


30 63 


25.20 


31 01 


25.54 


31.43 


25.88 


31.86 


62.3 


30.50 


25.09 


30 69 


25.25 


31 08 


25.59 


31.49 


25.94 


31 93 


62.4 


30.66 


25.14 


30.75 


25.81 


31.14 


25.65 


31.56 


25.99 


31 99 


62.5 


30 62 


25.20 


30 82 


25.36 


31.21 


25.70 


31 63 


26.05 


32 06 


62.6 


30 69 


25.25 


30 88 


25.42 


31.28 


25.76 


31 69 


26.11 


32 13 


62.7 


30.75 


2-5.31 


30 94 


25.47 


31.34 


25.81 


31.76 


26.17 


32 20 


62.8 


30.81 


25.86 


31.01 


25.58 


31.41 


25.87 


31 83 


26.28 


32 27 


62.9 


30.87 


25.42 


31.07 


25.58 


31.47 


25.92 


31.89 


26.29 


32 34 



XVI] 



WINES 



227 



Table — 


-Continued. 












, 


6 


21° c. 


22 


C. 


23 


'C. 


24 


'C. 


25 


C. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
READING 


by 


by 


by. 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




23.91 


29.47 


24.23 


29.87 


24.55 


30 27 


24.89 


30 69 


25.25 


58.0 


23.96 


29.54 


24.28 


29.93 


2 4. 61 


30.34 


24.95 


30.76 


25.31 


58.1 


24.02 


29.60 


24.34 


29.99 


24.66 


30.41 


25.01 


30.83 


25.37 


58.2 


24.07 


29.67 


24.39 


30.06 


24.72 


30.48 


25.07 


30 90 


25.4s 


58.3 


24.13 


29.73 


24.45 


30.13 


24.78 


30.54 


25.13 


30.97 


25.49 


58.4 


24.18 


29.80 


24.50 


30.20 


24.83 


30 61 


25.18 


31.04 


25.55 


58.5 


24.23 


29.86 


24.56 


30 26 


24.89 


30.68 


25.23 


31.11 


25.61 


58.6 


24.29 


29 93 


2 4. 61 


30 33 


24.94 


30.75 


25.29 


31.18 


25.67 


58.7 


24.34 


29.99 


24.67 


30.40 


25.00 


30.82 


25.35 


31.25 


25.73 


58.8 


24.40 


30.06 


24.72 


30.47 


25.06 


30.88 


25.41 


31.32 


25.80 


58.9 


24.45 


30 13 


24.78 


30 53 


25.12 


30 95 


25.47 


31.40 


25.86 


59.0 


24.51 


30 19 


24.83 


30.60 


25.18 


31.02 


25.53 


31.47 


25.92 


59.1 


24.56 


30.26 


24.89 


30.67 


25.24 


31.09 


25.59 


31.54 


25.98 


59.2 


24. 61 


30 33 


24.95 


30.74 


25.30 


31.16 


25.65 


31 61 


26.04 


59.3 


24.67 


30 39 


25.00 


30 81 


25.36 


31 23 


25.71 


31.68 


26.10 


59.4 


24.72 


30 46 


25.06 


30.87 


25.41 


31 30 


25.77 


31.76 


26.16 


59.5 


24.78 


30 53 


25.11 


30.94 


25.47 


31 38 


25.83 


31.83 


26.23 


59.6 


24.83 


30 59 


25.17 


31.01 


25.53 


31.45 


25.89 


31 90 


26.29 


59.7 


24.89 


30 66 


25.23 


31.08 


25.59 


31 52 


25.95 


31.97 


26.35 


59.8 


24.94 


30 73 


25.29 


31.15 


25.65 


31 59 


26.02 


32 04 


26.42 


59.9 


24.99 


30 79 


25.34 


31 22 


25.71 


31.66 


26.08 


32 12 


26.48 


60.0 


25.05 


30 86 


25.40 


31.29 


25.77 


31 73 


26.14 


32.19 


26.54 


60.1 


25.11 


30.93 


25.46 


31 36 


25.83 


31.80 


26.20 


32.27 


26.61 


60.2 


25.16 


30.99 


25.52 


31 43 


25.89 


31.87 


26.27 


32 34 


26.67 


60.3 


25.22 


31.06 


25.57 


31.50 


25.95 


31.94 


26.33 


32.41 


26.73 


60.4 


25.28 


31.13 


25.63 


31.57 


26.01 


32 02 


26.39 


32 49 


26.80 


60.5 


25.34 


31 20 


25.69 


31.64 


26.07 


32.09 


26.45 


32 56 


26.86 


60.6 


25.39 


31 27 


25.75 


31.71 


26.13 


32.16 


26.52 


32.64 


26.92 


60.7 


25.45 


31 33 


25.80 


31.78 


26.19 


32 23 


26.58 


32.71 


26.99 


60.8 


25.51 


31.40 


25.86 


31.85 


26.25 


32.30 


26.64 


32.78 


27.05 


60.9 


25.56 


31.47 


25.92 


31.92 


26.31 


32 38 


26.70 


32 86 


27 12 


61.0 


25.62 


31 54 


25.98 


31.99 


26.37 


32.45 


26.76 


32 93 


27.18 


61.1 


25.68 


31.61 


26.04 


32 06 


26.43 


32 52 


26.83 


33 01 


27.24 


61.2 


25.73 


31.67 


26.10 


32 13 


26.49 


32.59 


26.89 


33.08 


27.31 


61.3 


25.79 


31.74 


26.16 


32.20 


26.55 


32.67 


26.95 


33.16 


27.37 


61.4 


25.85 


31.81 


26.22 


32 27 


26.61 


32.74 


27.01 


33 23 


27.44 


61.5 


25.90 


31.88 


26.28 


32.34 


26.67 


32.81 


27.08 


33.31 


27.50 


61.6 


25.96 


31.95 


26.34 


32.41 


26.73 


32.88 


27.14 


33 38 


27.56 


61.7 


26.02 


32.01 


26.40 


32.49 


26.79 


32 96 


27.20 


33 46 


27.63 


61.8 


26.08 


32 09 


26.46 


32.56 


26.85 


33 03 


27.27 


33 53 


27.69 


61.9 


26.14 


32.16 


26.51 


32 63 


26.92 


33.10 


27.33 


33.60 


27.76 


62.0 


26.20 


32.23 


26.57 


32.70 


26.98 


33.18 


27.39 


33.68 


27.82 


62.1 


26.25 


32 30 


26.63 


32.77 


27.04 


33.25 


27.46 


33.75 


27.88 


62.2 


26.31 


32.37 


26.69 


32.84 


27.10 


33 33 


27.52 


33 83 


27.95 


62.3 


26.37 


32.44 


26.75 


32.91 


27.16 


33.40 


27.58 


33.90 


28.01 


62.4 


26.43 


32.51 


26.81 


32.99 


27.23 


33 47 


27.65 


33 98 


28.08 


62.5 


26.49 


32.68 


26.87 


33.06 


27.29 


33.55 


27.71 


34.05 


28.15 


62.6 


26.55 


32.65 


26.93 


33.13 


27.35 


33.62 


27.77 


34.13 


28.22 


62.7 


26.61 


32.72 


26.99 


33.20 


27.41 


33.70 


27.84 


34.21 


28.28 


62.8 


26.67 


32.79 


27.06 


33.28 


27.48 


33.77 


27.90 


34.29 


28.35 


62.9 



228 
6 



METHODS OF ANALYSIS 



[Chap. 



Table 17.— Alcohol 





17.5 


"C. 


18° 


C. 


19' 


C. 


20° 


C. 


21° C 


SCALE 
READING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


^y 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


63.0 


30 94 


25.^7 


31.14 


25.64 


31.54 


25.98 


31.96 


26.35 


32.41 


63.1 


31.00 


25.52 


31.20 


25.69 


31.61 


26.03 


32 03 


26.41 


32.48 


63.2 


31 06 


25.58 


31.26 


25.75 


31.67 


26.09 


32.10 


26.46 


32.66 


63.3 


31 13 


25.63 


31 33 


25.80 


31.74 


26.15 


32.17 


26.52 


32.62 


63.4 


31.19 


25.69 


31.39 


25.86 


31.80 


26.21 


32 23 


26.58 


32.69 


63.5 


31.26 


25.74- 


31 46 


25.91 


31.87 


26.26 


32 30 


26.64 


32.76 


63.6 


31 32 


25.80 


31 52 


25.97 


31 93 


26.32 


32 37 


26.70 


32.83 


63.7 


31 38 


25.85 


31 59 


26.02 


32 00 


26.38 


32.44 


26.76 


32.90 


63.8 


31.45 


25.91 


31 65 


26.08 


32.07 


26.44 


32 61 


26.82 


32.97 


63.9 


31.51 


25.96 


31.72 


26.13 


32.13 


26.49 


32.58 


26.88 


33 04 


64.0 


31.58 


26.02 


31.78 


26.19 


32 20 


26.55 


32.65 


26.94 


33.11 


64.1 


31.64 


26.07 


31.85 


26.25 


32 27 


26.61 


32 72 


26.99 


33.18 


64.2 


31.70 


26.13 


31.91 


26.30 


32.34 


26.67 


32 79 


27.05 


33 25 


64.3 


31 77 


26.18 


31.97 


26.36 


32.40 


26.72 


32 86 


27.11 


33 32 


64.4 


31 83 


26.24 


32.04 


26.41 


32.47 


26.78 


32 92 


27.17 


33 39 


64.5 


31 90 


26.29 


32.11 


26.47 


32.54 


26.84 


32.99 


27.23 


33.46 


64.6 


31 96 


26.35 


32.17 


26.53 


32.60 


26.90 


33 06 


27.29 


33.63 


64.7 


32 03 


26.40 


32.24 


26.58 


32 67 


26.95 


33 13 


27.35 


33.60 


64.8 


32.09 


26.46 


32.30 


26.64 


32.74 


27.01 


33 20 


27.41 


33.67 


64.9 


32 16 


26.51 


32.37 


26.69 


32 81 


27.07 


33 27 


27.47 


33.74 


65.0 


32.22 


26.57 


32 43 


26.75 


32 87 


27.13 


33 34 


27.53 


33.82 


65.1 


32.29 


26.63 


32 50 


26.80 


32.94 


27.19 


33 41 


27.59 


33 89 


65.2 


32 35 


26.68 


32.57 


26.86 


33 01 


27.25 


33.48 


27.65 


33 96 


65.3 


32 42 


26.74 


32.63 


26.92 


33.08 


27.31 


33 56 


27.71 


34.03 


65.4 


32.48 


26.79 


32.70 


26.97 


33 16 


27.37 


33 62 


27.77 


34.10 


65.5 


32 55 


26.85 


32.76 


27.03 


33 22 


27.43 


33.69 


27.83 


34.18 


65.6 


32.61 


26.90 


32 83 


27.09 


33.28 


27.49 


33 76 


27.89 


34 25 


65.7 


32.68 


26.96 


32 89 


27.15 


33 36 


27.54 


33 83 


27.95 


34.32 


65.8 


32.75 


27.01 


32.96 


27.21 


33 42 


27.60 


33 90 


28.01 


34.40 


65.9 


32.81 


27.07 


33 03 


27.26 


33 49 


27.66 


33.97 


28.07 


34.47 


66.0 


32.88 


27.13 


33.10 


27.32 


33.56 


27.72 


34.04 


28.13 


34.64 


66.1 


32.94 


27.19 


33 17 


27.38 


33 63 


27.78 


34.11 


28.19 


34 62 


66.2 


33 01 


27.25 


33 23 


27.44 


33 70 


27.84 


34.18 


28.26 


34 69 


66.3 


33 07 


27.30 


33 30 


27.50 


33.77 


27.90 


34.25 


28.32 


34.76 


66.4 


33.14 


27.36 


33 37 


27.56 


33 84 


27.96 


34 33 


28.38 


34.84 


66.5 


33.21 


27.42 


33 44 


27.62 


33 91 


28.02 


34.40 


28.45 


34 91 


66.6 


33 28 


27.48 


33 51 


27.68 


33 98 


28.08 


34.47 


28.51 


34 99 


66.7 


33 35 


27.54 


33.68 


27.73 


34.05 


28.14 


34.64 


28.57 


35 06 


66.8 


33 41 


27.60 


33.65 


27.79 


34.12 


28.20 


34.62 


28.64 


35 14 


66.9 


33.48 


27.65 


33.72 


27.85 


34.19 


28.27 


34 69 


28.70 


35.21 


67.0 


33 65 


27.71 


33.79 


27.91 


34.26 


28.33 


34.76 


28.76 


35.29 


67.1 


33 62 


27.77 


33 86 


27.97 


34 34 


28.39 


34.83 


28.82 


35 37 


67.2 


33 69 


27.83 


33 92 


28.03 


34.41 


28.45 


34.91 


28.89 


36.44 


67.3 


33.76 


27.89 


33.99 


28.09 


34.48 


28.52 


34.98 


28.95 


36 52 


67.4 


33.82 


27.95 


34.06 


28.15 


34.56 


28.58 


36 06 


29.01 


36.60 


67.5 


33 89 


28.01 


34 13 


28.21 


34 62 


28.64 


36.13 


29.08 


36.67 


67.6 


33.96 


28.06 


34 20 


28.27 


34.69 


28.70 


35,20 


29.14 


35.75 


67.7 


34.03 


28.12 


34.27 


28.34 


34.76 


28.76 


35.28 


29.21 


35.82 


67.8 


34.09 


28.18 


34.34 


28.40 


34 84 


28.83 


35.36 


29.27 


35.90 


67.9 


34.16 


28.24 


34 41 


28.46 


34 91 


28.89 


35.43 


29.34 


35 98 



XVI] 



WINES 



229 



Table — 


-Continued. 














6 


21° c. 


22° 


c. 


23° 


c. 


24° 


c. 


25 


C. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
RE\DINO 


by 


by 


'?y. 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




26.73 


32.87 


27.12 


33 35 


27.54 


33 84 


27.96 


34 36 


28.42 


63.0 


26.79 


32 94 


27.18 


33.42 


27.60 


33 92 


28.03 


34.44 


28.49 


63.1 


26.85 


33.01 


27.24 


33.50 


27.66 


33 99 


28.09 


34 52 


28.55 


63.2 


26. 9 1 


33 08 


27.31 


33.57 


27.72 


34.07 


28.16 


34.60 


28.62 


63.3 


26.96 


33 15 


27.37 


33.64 


27.79 


34.15 


28.23 


34.67 


28.69 


63.4 


27.02 


33.22 


27.43 


33 72 


27.85 


34.22 


28.29 


34.75 


28.76 


63.5 


27.09 


33 30 


27.49 


33.79 


27.91 


34 30 


28.36 


34.83 


28.82 


63.6 


27.15 


33 37 


27.56 


33 86 


27.98 


34 38 


28.43 


34.91 


28.89 


63.7 


27.21 


33 44 


27.62 


33 93 


28.04 


34.45 


28.49 


34.98 


28.96 


63.8 


27.27 


33 51 


27.68 


34.01 


28.11 


34 53 


28.56 


35.07 


29.03 


63.9 


27.33 


33 59 


27.74 


34.08 


28.17 


34 61 


28.63 


35 15 


29.10 


64.0 


27.39 


33.66 


27.81 


34.16 


28.24 


34.68 


28.69 


35 23 


29.17 


64.1 


27.J1.5 


33 73 


27.87 


34.23 


28.30 


34.76 


28.76 


35 31 


29.24 


64.2 


27.51 


33 80 


27.93 


34.31 


28.37 


34.84 


28.83 


35 39 


29.31 


64.3 


27.57 


33.88 


27.99 


34 39 


28.43 


34 92 


28.89 


35.48 


29.38 


64.4 


27.63 


33 95 


28.06 


34.46 


28.50 


34 99 


28.96 


36 56 


29.45 


64.5 


27.70 


34,02 


28.12 


34.54 


28.57 


35.07 


29.03 


35.64 


29.52 


64.6 


27.76 


34 10 


28.19 


34.61 


28.63 


35.15 


29.10 


35.72 


29.60 


64.7 


27.82 


34.17 


28.25 


34.69 


28.70 


35 23 


29.17 


35 80 


29.67 


64.8 


27.88 


34.24 


28.81 


34.76 


28.76 


35 31 


29.24 


35 89 


29.74 


64.9 


27.94 


34 32 


28.38 


34.84 


28.83 


35 39 


29.31 


35 97 


29.81 


65.0 


28.00 


34 39 


28.44 


34 92 


28.89 


35 47 


29.38 


36.05 


29.88 


65.1 


28.06 


34.47 


28.51 


34.99 


28.96 


35 55 


29.44 


36.13 


29.95 


65.2 


28.13 


34.64 


28.57 


35 07 


29.03 


35 63 


29.51 


36 21 


30.02 


65.3 


28.19 


34.61 


28.63 


35 15 


29.10 


35 71 


29.58 


36 30 


80.10 


65.4 


28.25 


34.69 


28.70 


35 23 


29.16 


35.79 


29.65 


36 38 


30.17 


65.5 


28.32 


34.76 


28.76 


35 30 


29.23 


35 87 


29.72 


36 46 


80.24 


65.6 


28.38 


34.84 


28.83 


35 38 


29.30 


35 94 


29.79 


36 55 


30.82 


65.7 


28.45 


34 91 


28.89 


35.46 


29.37 


36.02 


29.86 


36.63 


30.39 


65.8 


28.51 


34.99 


28.96 


35.54 


29.44 


36.11 


29.93 


36.71 


30.46 


65.9 


28.57 


35 06 


29.02 


35.62 


29.51 


36 19 


30.00 


36 79 


30.54 


66.0 


28.64 


35 14 


29.09 


35.70 


29.58 


36.27 


80.07 


36.88 


80.61 


66.1 


28.70 


35 22 


29.16 


35.77 


29.64 


36 35 


30.15 


36 96 


30.68 


66.2 


28.76 


35 30 


29.23 


35.85 


29.71 


36 43 


30.22 


37 04 


30.76 


66.3 


28.83 


35 38 


29.29 


35 93 


29.78 


36.52 


30.29 


37 13 


30.83 


66.4 


28.89 


35.45 


29.36 


36 01 


29.85 


36 60 


30.86 


37.22 


30.90 


66.5 


28.96 


35 53 


29.43 


36 09 


29.92 


36 68 


30.43 


37 30 


30.98 


66.6 


29.03 


35.61 


29.50 


36 17 


29.99 


36 76 


30.51 


37 39 


31.05 


66.7 


29.09 


35 69 


29.57 


36 25 


30.06 


36 84 


30.58 


37.48 


31.13 


66.8 


29.15 


35.77 


29.64 


36 33 


30.13 


36.93 


30.65 


37 57 


31.21 


66.9 


29.22 


35.84 


29.71 


36 41 


30 . 20 


37 01 


30.72 


37.65 


31.28 


67.0 


29.29 


35 92 


29.77 


36 49 


30.27 


37 09 


30.80 


37.74 


31 . 36 


67.1 


29.35 


36.00 


29.84 


36.57 


30.34 


37.18 


30.87 


37 83 


31.44 


67.2 


29.42 


36 08 


29.91 


36 65 


30.41 


37 26 


80.94 


37.91 


31.51 


67.3 


29.49 


36 16 


29.98 


36 73 


30.49 


37 35 


31.02 


38 00 


81.59 


67.4 


29.55 


36.24 


30.05 


36 81 


30.56 


37.44 


81.09 


38 09 


81.65 


67.5 


29.62 


36.32 


SO. 12 


36 90 


30.63 


37 52 


81.17 


38.18 


31.74 


67.6 


29.69 


36 40 


30.19 


36.98 


30.70 


37.61 


81.24 


38 26 


31.82 


67.7 


29.75 


36.48 


30.26 


37.06 


30.77 


37.69 


31.32 


38.35 


31.89 


67.8 


29.82 


36.56 


30.33 


37.14 


30.84 


37.78 


31.89 


38.44 


81.97 


67.9 



230 



METHODS OF ANALYSIS 



[Chap. 



Table 17.— Alcohol 





17.5 


"C. 


18= 


C. 


19° 


c. 


20° 


C. 


21° C. 


SCALE 
READING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


68.0 


34.23 


28.30 


34.48 


28.52 


34.98 


28.95 


35.50 


29.41 


36 05 


68.1 


34.30 


28.36 


34.56 


28.58 


35 05 


29.01 


35.57 


29.47 


36.13 


68.2 


34.36 


28.42 


34.62 


28.64 


35.13 


29.08 


35.65 


29.54 


36.21 


68.3 


34.43 


28.48 


34.69 


28.70 


35 20 


29.14 


35 72 


29.60 


36.29 


68.4 


34.50 


28.54 


34.76 


28.76 


35.27 


29.21 


35 80 


29.67 


36.37 


68.5 


34.57 


28.59 


34.83 


28.82 


35 35 


29.27 


35 87 


29.73 


36 45 


68.6 


34.64 


28.65 


34.90 


28.88 


35.42 


29.33 


35.95 


29.80 


36.52 


68.7 


34.70 


28.71 


34.97 


28.95 


35.49 


29.40 


36.02 


29.86 


36.60 


68.8 


34.77 


28.77 


35.04 


29.01 


35.57 


29.46 


36.10 


29.93 


36.68 


68.9 


34.84 


28.83 


35.12 


29.07 


35 64 


29.53 


36.18 


29.99 


36.76 


69.0 


34.91 


28.89 


35.19 


29.13 


35.71 


29.59 


36.25 


30.06 


36.84 


69.1 


34.97 


28.95 


35.26 


29.19 


35.79 


29.65 


36 33 


30.13 


36 91 


69.2 


35.04 


29.01 


35 33 


29.26 


35.86 


29.72 


36.41 


30.20 


36 99 


69.3 


35 12 


29.07 


35.40 


29.32 


35.93 


29.78 


36.48 


30.27 


37.07 


69.4 


35.19 


29.14 


35 47 


29.38 


36 01 


29.85 


36.56 


30.33 


37.16 


69.5 


35.27 


29.20 


35.55 


29.45 


36.08 


29.91 


36.64 


30.40 


37.24 


69.6 


35 34 


29.26 


35.62 


29.51 


36,16 


29.97 


36.72 


30.47 


37.32 


69.7 


35.41 


29.33 


35.69 


29.57 


36 23 


30.04 


36.79 


30.54 


37.40 


69.8 


35 49 


29.39 


35.76 


29.64 


36.31 


30.11 


36.87 


30.61 


37.48 


69.9 


35.56 


29.46 


35 83 


29.70 


36 39 


30.17 


36.95 


30.67 


37.66 


70.0 


35.64 


29.52 


35 91 


29.76 


36 46 


30.24 


37.02 


30.74 


37.64 


70.1 


35.71 


29.59 


35 98 


29.82 


36.54 


30.31 


37.10 


30.81 


37.72 


70.2 


35 78 


29.65 


36 05 


29.89 


36 61 


30.38 


37.19 


30.88 


37.80 


70.3 


35 86 


29.72 


36 13 


29.95 


36.69 


30.44 


37 27 


30.95 


37 89 


70.4 


35.93 


29.78 


36.20 


30.01 


36.76 


30.51 


37 35 


31.01 


37.97 


70.5 


36.01 


29.85 


36.28 


30.08 


36.84 


30.58 


37.43 


31.09 


38.06 


70.6 


36.08 


29.91 


36 35 


30.15 


36.92 


30.64 


37.51 


31.16 


38.13 


70.7 


36.16 


29.97 


36.43 


30.21 


36 99 


30.71 


37 59 


31.23 


38.22 


70.8 


36 23 


30.04 


36.50 


30.28 


37 07 


30.78 


37.67 


31.30 


38 30 


70.9 


36 31 


30.11 


36.58 


30.35 


37.15 


30.85 


37 76 


31.37 


38.38 


71.0 


36.38 


30.17 


36.65 


30.41 


37 23 


30.91 


37.83 


31.44 


38.47 


71.1 


36,46 


30.24 


36 73 


30.48 


37.31 


30.98 


37 91 


31.51 


38.55 


71.2 


36 53 


30.30 


36.80 


30.55 


37.39 


31.05 


37 99 


31.59 


38 63 


71.3 


36 60 


30.37 


36.88 


30.61 


37.47 


31.12 


38 07 


31.66 


38.72 


71.4 


36.68 


30.44 


36.95 


30.68 


37.55 


31.19 


38.16 


31.73 


38.80 


71.5 


36.75 


30.50 


37.03 


30.75 


37.63 


31.26 


38.24 


31.80 


38.88 


71.6 


36.83 


30.57 


37.11 


30.81 


37.71 


31.33 


38 32 


31.87 


38.97 


71.7 


36.90 


30.64 


37.19 


30.88 


37.79 


31.40 


38.40 


31.94 


39 05 


71.8 


36.98 


30.70 


37.27 


30.95 


37.87 


31.47 


38.49 


32.01 


39.14 


71.9 


37.05 


30.77 


37.34 


31.01 


37.94 


31.54 


38.57 


32.09 


39 23 


72.0 


37 13 


30.84 


37 42 


31.08 


38.02 


31.61 


38.65 


32.17 


39 31 


72.1 


37.21 


30.90 


37 50 


31.15 


38.11 


31.68 


38.74 


32.24 


3d. 40 


72.2 


37 29 


30.97 


37.58 


31.22 


38 19 


31.75 


38 82 


32.32 


39.49 


72.3 


37 36 


31.03 


37.66 


31.29 


38 27 


31.82 


38 90 


32.39 


39.57 


72.4 


37.44 


31.10 


37.73 


31.36 


38 35 


31.89 


38 98 


32.47 


39 66 


72.5 


37.52 


31.17 


37.81 


31.42 


38.43 


31.96 


39.07 


32.54 


39 75 


72.6 


37.60 


31.24 


37 89 


81.49 


38.51 


32.04 


39.16 


32.62 


39 83 


72.7 


37.67 


31.31 


37.97 


31.56 


38 59 


32.11 


39.24 


32.69 


39.92 


72.8 


37.75 


31.37 


38 05 


31.63 


38.67 


32.18 


39 33 


32.77 


40.01 


72.9 


37 83 


31.44 


38.13 


31.70 


38.76 


32.26 


39 41 


32.84 


40.10 



XVI] 



Table.— Continued. 



WINES 



231 
6 



21° C. 


22° 


c. 


23° 


C. 


24° 


c. 


25° 


c. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
READING 


by 


by 


by 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 




29.89 


36 63 


30.40 


37 23 


30.91 


37.86 


31.47 


38.63 


32.05 


68.0 


29.95 


36 71 


30.47 


37 31 


30.99 


37.95 


31.54 


38 61 


32.13 


68.1 


30.02 


36 79 


30.54 


37 39 


31.06 


38.03 


31.62 


38.70 


32.21 


68.2 


30.09 


36 87 


30.61 


37 48 


31.13 


38.12 


31.69 


38.79 


32.29 


68.3 


30.16 


36 96 


30.68 


37.56 


31.21 


38.21 


31.77 


38.88 


32.37 


68.4 


30.2?i 


37 03 


30.75 


37 65 


31.28 


38 30 


31.84 


38 96 


32.45 


68.5 


30.30 


37.12 


30.82 


37 73 


31.35 


38 38 


31.92 


39 06 


32.53 


68,6 


SO. 37 


37 20 


30.89 


37.82 


31.43 


38.47 


31.99 


39.16 


32.61 


68 7 


30.43 


37 28 


30.96 


37 90 


31.50 


38 56 


32.07 


39 24 


32.69 


68 8 


30.50 


37 36 


31.03 


37 98 


31.57 


38 64 


32.15 


39 33 


32.77 


68.9 


SO. 57 


37 45 


31.10 


38 07 


31.65 


38.73 


32.23 


39.43 


32.86 


69 


30.64 


37 53 


31.17 


38.15 


31.72 


38.82 


32.31 


39 62 


32.94 


69.1 


SO. 71 


37 61 


31.25 


38.24 


31.79 


38.90 


32.39 


39 61 


33.02 


69 2 


30.78 


37 69 


31.32 


38.32 


31.87 


38 99 


32.47 


39.70 


33.10 


69.3 


30.85 


37 78 


31.39 


38.41 


31.94 


39 08 


32.55 


39.80 


33.18 


69.4 


30.92 


37 86 


31.46 


38 50 


32.02 


39 17 


32.63 


39 89 


33.26 


69.5 


SO. 99 


37.94 


31.54 


38 68 


32.09 


39 26 


32.71 


39.98 


33.34 


69.6 


31.06 


38 03 


31.61 


38 67 


32.17 


39 35 


32.78 


40.07 


33.43 


69.7 


31 . 13 


38 11 


31.68 


38 75 


32.25 


39 46 


32.86 


40.17 


33.51 


69.8 


31.20 


38 19 


31.75 


38.84 


32.33 


39.54 


32.95 


40.26 


33.59 


69.9 


SI. 27 


38 28 


31.83 


38 92 


32.41 


39 63 


33.02 


40 35 


33.67 


70.0 


31.35 


38 36 


31.90 


39 01 


32.49 


39.72 


33.11 


40.44 


S3. 7 5 


70.1 


SI. 42 


38.45 


31.97 


39 10 


32.57 


39.81 


33.19 


40 63 


33.84 


70.2 


31.49 


38 53 


32.05 


39.19 


32.65 


39 90 


33.27 


40.62 


33.92 


70.3 


31.56 


38 61 


32.12 


39.28 


32.72 


39.99 


33.35 


40.72 


34.00 


70.4 


31.63 


38 70 


32.20 


39 37 


32.80 


40.08 


33.43 


40.81 


3 4. 08 


70.5 


SI. 70 


38 78 


32.28 


39.46 


32.88 


40.17 


33.51 


40.90 


34.17 


70.6 


31.78 


38 87 


32.36 


39.66 


32.96 


40.26 


33.59 


40.99 


34.25 


70.7 


31.85 


38 95 


32.43 


39.64 


33.04 


40 36 


33.68 


41.08 


34.33 


70.8 


31.92 


39.04 


32.51 


39.73 


33.12 


40.46 


33.76 


41.18 


34.4^ 


70.9 


31.99 


39 12 


32.59 


39 82 


33.20 


40.64 


33.84 


41.27 


34.50 


71.0 


32.07 


39 21 


32.67 


39.91 


33.28 


40.63 


33.92 


41.36 


34.58 


71.1 


32.15 


39 30 


32.74 


40 00 


33.36 


40.72 


34.00 


41.46 


34.67 


71.2 


32.22 


39 39 


32.82 


40.09 


33.44 


40.81 


3 4. 08 


41.56 


34.75 


71.3 


32.30 


39.48 


32.90 


40.18 


33.52 


40.90 


34.17 


41.64 


34.83 


71.4 


32.37 


39.57 


32.98 


40.27 


33.60 


40.99 


34.25 


41.74 


34.92 


71.5 


32.45 


39 65 


33.05 


40.36 


33.68 


41.08 


34.33 


41.83 


35.00 


71.6 


32.53 


39.74 


33. IS 


40.45 


33.76 


41.18 


34.41 


41.93 


35.08 


71.7 


32.60 


39:83 


33.21 


40.54 


33.84 


41.27 


34.50 


42.02 


35.17 


71.8 


32.68 


39.92 


33.29 


40.63 


33.92 


41.36 


34.58 


42.11 


35.25 


71.9 


32.76 


40.01 


33.37 


40.72 


34.00 


41.45 


34.66 


42.21 


35.34 


72.0 


32.83 


40.10 


33.45 


40 81 


34. 08 


41.55 


34.74 


42.30 


35.42 


72.1 


S2.91 


40 18 


33.52 


40.90 


34.16 


41.64 


34.83 


42.40 


35.51 


72.2 


32.98 


40 27 


33.60 


40.99 


34.24 


41.73 


34.91 


42.49 


35.59 


72.3 


33.06 


40 36 


33.68 


41.08 


34.33 


41.82 


34.99 


42.68 


35.68 


72.4 


33.14 


40.45 


33.76 


41,17 


34.41 


41.92 


35.08 


42.68 


35.76 


72.5 


33.22 


40 54 


33.84 


41.26 


34.49 


42.01 


35.16 


42.77 


35.85 


72.6 


33.29 


40.62 


33.91 


41.35 


34.57 


42.10 


35.24 


42,87 


35.93 


72.7 


33.37 


40.71 


33.99 


41.45 


34.65 


42.19 


35.33 


42.96 


36.02 


72.8 


SS.45 


40.80 


34.07 


41.54 


34.73 


42.29 


35.41 


43.06 


36.10 


72.9 



232 



METHODS OF ANALYSIS 



[Chap. 



6 














Table 17.— Alcohol 




17.5 


"C. 


18° 


C. 


19° 


c. 


20° 


C. 


21° C. 


SCALE 
READING 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 




by 


by 


by 


by 


by 


by 


by 


by 


by 




volume 


weight 


volume 


weight 


volume 


weight 


volume 


weight 


volume 


73.0 


37 91 


31.51 


38 21 


31.77 


38.84 


32 . 33 


39 60 


32.92 


40 18 


73.1 


37 98 


31.58 


38 29 


31.84 


38 92 


32.40 


39 69 


32.99 


40.27 


73.2 


38 06 


31.65 


38 37 


31.90 


39 00 


32.48 


39.67 


33.07 


40 36 


73.3 


38 14 


31 . 71 


38 45 


31.97 


39 08 


32.55 


39 76 


33.15 


40.44 


73.4 


38 22 


31.78 


38 63 


32.04 


39 17 


32 . 62 


39 84 


33.22 


40 63 


73.5 


38 30 


31.85 


38 61 


32.12 


39 25 


32.70 


39.93 


33.30 


40.62 


73.6 


38 38 


31.92 


38 69 


32.19 


39.34 


32.77 


40 02 


33.37 


40.70 


73.7 


38 46 


31.99 


38 77 


32.26 


39 42 


32.85 


40.10 


33.45 


40.79 


73.8 


38 64 


32.06 


38 86 


32.34 


39 60 


32.92 


40 19 


33.55 


40.88 


73.9 


38 62 


32.13 


38 93 


32.41 


39 69 


32.99 


40.28 


33.60 


40.97 


74.0 


38 70 


32.20 


39 01 


32.48 


39 67 


33.07 


40 36 


33.68 


41.06 


74.1 


38.78 


32.27 


39 09 


32.55 


39 76 


33.15 


40 45 


33.76 


41 14 


74.2 


38 86 


32.35 


39 18 


32.63 


39 84 


33.22 


40 63 


33.83 


41.23 


74.3 


38 94 


32.42 


39 26 


32.70 


39 92 


33.30 


40 62 


33.91 


41 32 


74.4 


39 02 


32.49 


39 34 


32.77 


40 01 


33.37 


40.71 


33.98 


41.41 


74.5 


39 10 


32.56 


39 43 


32.85 


40 09 


33.45 


40.79 


34.06 


41.60 


74.6 


39 18 


32.63 


39 51 


32.92 


40.18 


33.53 


40 88 


34.14 


41 69 


74.7 


39.26 


32.70 


39 69 


32.99 


40.27 


33.60 


40 97 


34.22 


41.68 


74.8 


39 36 


32.78 


39 68 


33.07 


40 35 


33.68 


41.05 


34.30 


41.77 


74.9 


39 43 


32.85 


39 76 


33.15 


40 44 


33.76 


41.14 


34.58 


41.86 


75.0 


39 61 


32.92 


39 84 


33.22 


40 63 


33.83 


41.23 


34-46 


41 96 


75.1 


39.60 


32.99 


39 93 


33.30 


40 61 


33.91 


41 32 


34.54 


42.04 


75.2 


39 68 


33.07 


40 01 


33.37 


40 70 


33.98 


41.41 


34-61 


42.13 


75.3 


39 76 


33.15 


40 09 


33.45 


40 78 


34. 06 


41 60 


34-69 


42 22 


75.4 


39 84 


33.22 


40.18 


33.53 


40 87 


34.14 


41 68 


34.77 


42.31 


75.5 


39 93 


33.30 


40.27 


33.60 


40 96 


34-22 


41 67 


54-85 


42.40 


75.6 


40.01 


33.37 


40 36 


33.68 


41 04 


34.30 


41.76 


54-93 


42 49 


75.7 


40 09 


33.45 


40 44 


33.76 


41.13 


34.38 


41 86 


55.01 


42 58 


75.8 


40 18 


33.53 


40.53 


33.88 


41.22 


34.45 


41.94 


55.09 


42.67 


75.9 


40 27 


33.60 


40 61 


33.91 


41 31 


34.53 


42 03 


55.17 


42.76 


76.0 


40 36 


33.68 


40 70 


33.98 


41.40 


34. 61 


42 12 


55.25 


42.85 


76.1 


40.44 


33.76 


40.78 


34. 06 


41.48 


34.68 


42.21 


55.55 


42.96 


76.2 


40 63 


33.83 


40.87 


34.14 


41.67 


34.77 


42 30 


55.41 


43 04 


76.3 


40.61 


33.91 


40 96 


34.22 


41.66 


34.84 


42 39 


55.50 


43.13 


76.4 


40.70 


33.98 


41.04 


34.29 


41.76 


34.92 


42.48 


55.58 


43.22 


76.5 


40.78 


34.06 


41.13 


34.37 


41.83 


35.00 


42.57 


85.66 


43.32 


76.6 


40 87 


34.14 


41 22 


34.45 


41.92 


35.08 


42 66 


55.74 


43.41 


76.7 


40.96 


34.22 


41.30 


34.53 


42.01 


35.16 


42.75 


55.82 


43.50 


76.8 


41.04 


34.29 


41 39 


34. 60 


42.10 


35.24 


42.84 


55.90 


43.60 


76.9 


41.13 


34.37 


41.48 


34.68 


42.19 


35.32 


42.93 


55.98 


43.69 


77.0 


41.22 


34.45 


41. OT 


34.76 


42.28 


35.40 


43.02 


56.07 


43.79 


77.1 


41.31 


34.52 


41.65 


34.84 


42 37 


35.48 


43.11 


56.15 


43.88 


77.2 


41 39 


34. 60 


41.74 


34.91 


42.46 


35.56 


43.20 


56.24 


43.97 


77.3 


41.48 


34.68 


41.83 


34.99 


42.64 


35.64 


43 30 


86.52 


44.07 


77.4 


41.57 


34.75 


41.91 


35.07 


42.63 


35.72 


43.39 


56.40 


44.16 


77.5 


41.66 


34.83 


42.00 


35.15 


42.72 


35.80 


43.48 


56.49 


44.26 


77.6 


41.76 


34.91 


42.09 


35.23 


42.81 


35.88 


43.67 


56.67 


44.35 


77.7 


41 83 


34.98 


42.17 


35.30 


42.90 


35.96 


43.67 


56.66 


44.45 


77.8 


41.92 


35.06 


42.26 


35.38 


42 99 


36.04 


43.76 


56.74 


44.64 


77.9 


42.01 


35.14 


42.35 


35.46 


43.08 


36.13 


43.85 


56.82 


44.64 



XVI] 



Table.— Continued. 



WINES 



233 
6 



21° C. 


22 


'C. 


23 


C. 


24 


C. 


25 


'C. 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


SCALE 
RBADINQ 


by 


by 


by 


by 


by 


by 


by 


by 


by 




weight 


volume 


weight 


volume 


weight 


vohimo 


weight 


volume 


weight 




33.52 


40 88 


34.15 


41.63 


34.81 


42.38 


35.49 


43 16 


36.18 


73.0 


S3. 60 


40.97 


34.23 


41.72 


34-89 


42.47 


35.68 


43 24 


36.27 


73.1 


33.68 


41.06 


34-31 


41 81 


34-98 


42.56 


35.66 


43 33 


36.35 


73.2 


33.75 


41.16 


34.39 


41 90 


35.06 


42.66 


36.74 


43 43 


86.43 


73.3 


33.83 


41.24 


34-47 


41.99 


35.14 


42.75 


35.83 


43 62 


86.52 


73.4 


33.91 


41 33 


34-65 


42 08 


36.22 


42 84 


36.91 


43 61 


36.60 


73.5 


33.98 


41.42 


34-63 


42.17 


35.31 


42 93 


35.99 


43 70 


36.68 


73.6 


S4.06 


41 51 


34-71 


42 27 


35.39 


43 03 


36.08 


43 80 


36.77 


73.7 


34.14 


41 60 


34-79 


42 36 


35.47 


43 12 


36.16 


43 89 


36.86 


73.8 


34.22 


41.69 


34.87 


42.45 


35.55 


43 21 


36.24 


43 98 


36.93 


73.9 


34.30 


41.78 


34.96 


42 54 


35.64 


43 31 


36.33 


44 08 


37.02 


74.0 


34.38 


41.87 


35.03 


42 63 


35.72 


43 40 


36.41 


44.18 


37.11 


74.1 


34.46 


41 96 


36.12 


42.72 


35.80 


43 49 


36.49 


44 28 


37.20 


74.2 


34.54 


42.06 


35.20 


42 82 


35.88 


43 58 


36.58 


44.38 


37.29 


74.3 


34.62 


42 16 


35.28 


42 91 


35.97 


43.68 


36.66 


44.48 


37.38 


74.4 


34.70 


42 24 


35.36 


43 00 


36.06 


43 77 


36.74 


44.57 


37.47 


74.5 


34.78 


42 33 


36.45 


43 09 


36.13 


43 86 


36.83 


44.67 


37.66 


74.6 


34.86 


42.42 


35.53 


43 19 


36 . 22 


43.96 


36.91 


44.77 


37.66 


74.7 


34.94 


42 51 


36.61 


43.28 


36.30 


44.06 


36.99 


44 87 


37.76 


74.8 


35.02 


42.61 


36.69 


43 37 


36.39 


44 16 


37.08 


44.97 


87.84 


74.9 


36.10 


42.70 


36.78 


43 46 


36.47 


44.26 


37.17 


45 07 


37.98 


75.0 


35.18 


42.79 


35.86 


43 66 


36.55 


44.34 


37.26 


46 18 


88.02 


75.1 


35.26 


42.88 


35.95 


43 65 


36.64 


44.44 


37.36 


45 29 


88.12 


75.2 


36.34 


42.97 


36.03 


43.74 


36.72 


44.53 


37.44 


45 39 


38.21 


75.3 


35.43 


43.07 


36.11 


43.83 


36.81 


44.63 


37.53 


45 60 


38.31 


75.4 


35.51 


43.16 


36.20 


43.92 


36.89 


44.73 


37.62 


45 61 


88.40 


75.5 


35.69 


43.25 


36.28 


44.02 


36.97 


44.83 


37.71 


45 71 


38.50 


75.6 


35.67 


43 35 


36.36 


44.12 


37.06 


44 93 


37.80 


46.82 


88.60 


75.7 


36.75 


43.44 


36.45 


44.21 


37.15 


46 03 


37.89 


46 92 


88.69 


75.8 


35.84 


43.63 


36.53 


44.31 


37.24 


45.13 


37.98 


46 02 


88.79 


75.9 


36.92 


43.63 


36.62 


44.41 


37.33 


45 24 


38.08 


46 12 


38.88 


76.0 


36.00 


43.72 


36.70 


44.50 


37.42 


46 34 


38.17 


46.23 


38.98 


76.1 


36.08 


43 81 


36.79 


44.60 


37.50 


46.44 


38.27 


46 34 


39.08 


76.2 


36.17 


43.91 


36.87 


44.70 


37.59 


45 56 


38.36 


46.45 


39.18 


76.3 


36.25 


44.00 


36.96 


44.80 


37.68 


46 66 


38.46 


46.66 


89.29 


76.4 


36.34 


44.10 


37.04 


44.89 


37.77 


46 76 


38.55 


46 67 


39.89 


76.5 


36.42 


44.19 


37.13 


44.99 


37.86 


46 86 


38.66 


46 78 


39.49 


76.6 


36. 5 1 


44.29 


37.22 


46.09 


37.95 


46.96 


38.74 


46.89 


39.69 


76.7 


36.59 


44.38 


37.30 


45.19 


38.04 


46.07 


38.84 


47.00 


39.69 


76.8 


36.68 


44.48 


37.39 


45.30 


38.13 


46.18 


38.93 


47.11 


39.80 


76.9 


36.76 


44.57 


37.47 


46 40 


38.23 


46 29 


39.03 


47.23 


89.90 


77.0 


36.85 


44.67 


37.56 


45.60 


38.32 


46.40 


39.13 


47.34 


40.00 


77.1 


36.93 


44.76 


37.66 


46.60 


38.42 


46.51 


39.23 


47 45 


40.11 


77.2 


37.02 


44.86 


37.73 


46.70 


38.51 


46.62 


39.34 


47.67 


40.22 


77.3 


37.10 


44.96 


37.82 


45.81 


38.60 


46.73 


39.44 


47.68 


40.82 


77.4 


37.19 


45.06 


37.91 


45.91 


38.70 


46.84 


39.54 


47,80 


40.43 


77.5 


37.28 


45.15 


37.99 


46.01 


38.79 


46.96 


39.64 


47.91 


40.64 


77.6 


37.36 


46.26 


38.08 


46.12 


38.89 


47.06 


39.74 


48.02 


40.66 


77.7 


37.45 


45.35 


38.18 


46.23 


38.98 


47.17 


39.86 


48.14 


40.75 


77.8 


37.53 


45.46 


38.27 


46.34 


39.08 


47.28 


39.95 


48.26 


40.86 


77.9 



234 



METHODS OF ANALYSIS 



[Chap. 



Table 17. — ALgoHOL 





17.5 


'C. 


18 


C. 


19° 


C. 


20° 


C. 


21° C. 


READING 


Per cent 

by 
volume 


Per cent 

by 
weight 


Per cent 

by 
volume 


Per cent 

by, 

weight 


Per cent 
volume 


Per cent 
weight 


Per cent 

by 
volume 


Per cent 

by 
weight 


Per cent 

by 
volume 


78.0 

78.1 
78.2 
78.3 

78.4 


42.09 
42.18 
42.26 
42 36 
42.44 


35.22 
85.30 
35.38 
35.45 
35.53 


42.43 
42.52 
42.61 
42.70 
42.78 


35.54 
35.62 
35.70 
35.77 
35.85 


43.17 
43.27 
43 36 
43 45 

43.64 


36.21 
36.29 
36.38 
36.46 
36.54 


43.94 
44.04 
44.13 
44.23 
44.32 


36.91 
36.99 
37.08 
37.16 
37.25 


44.73 
44.83 
44.92 
45.02 
46.12 


78.5 
78.6 
78.7 
78.8 
78.9 


42.62 
42.61 
42.69 
42.78 
42.86 


35.61 
35.69 
35.77 
35.84 
35.92 


42.87 
42.96 
43.06 
43.14 
43.23 


35.93 
36.01 
36.09 
36.17 
36.26 


43 63 
43.72 
43 82 
43.91 
44.00 


36.63 
36.71 
36.79 
36.88 
36.96 


44.42 
44.51 
44.60 
44.70 
44.79 


37.33 
37.42 
37.50 
37.59 
37.68 


46.22 
45.32 
46.42 
45.62 
46.62 


79.0 
79.1 
79.2 
79.3 
79.4 


42.96 
43.04 
43.13 
43.22 
43.31 


36.00 
36.08 
36.16 
36.25 
36.33 


43 32 
43.41 
43 60 
43.59 
43.68 


36.34 
36.42 
36.50 
36.59 
36.67 


44 09 
44.19 
44.28 
44.38 
44.47 


37.04 
37.13 
37.21 
37.30 
37.38 


44.89 
44.98 
46.08 
45.18 
45.28 


37.76 
37.85 
37.94 
38.02 
38.11 


46.72 
46.82 
46.92 
46.02 
46.13 


79.5 
79.6 
79.7 
79.8 
79.9 


43.40 
43.49 
43.58 
43.67 
43.76 


36.41 
36.49 
36.57 
36.66 
36.74 


43.77 
43 86 
43.95 
44.05 
44.14 


36.75 
36.83 
36.92 
37.00 
37.09 


44.56 
44.65 
44,75 
44.84 
44.93 


37.47 
37.56 
37.64 
37.73 
37.81 


46.38 
46.48 
45.58 
45.68 
45.78 


38.20 
38.30 
38.39 
38.48 
38.57 


46.24 
46.34 
46.46 
46.56 
46.67 


80.0 


43.85 


36.82 


44.24 


37.17 


46.04 


37.90 


45.88 


38.67 


46.77 



XVIJ 



Table— Concluded. 



WINES 



235 
6 



21° C. 


22 


c. 


23° 


c. 


24° 


c. 


25° 


c. 




Per cent 

by 
weight 


Per cent 

by 
volume 


Per cent 
weight 


Per cent 

by 
volume 


Per cent 

by 
weight 


Per cent 

by 
volume 


Per cent 

by 
weight 


Per cent 

by 
volume 


Per cent 

by 
weight 


SCALE 
READING 


37.62 
37.71 
37.79 
37.88 
37.97 


46 66 
46.66 
46.76 
46.86 
45.96 


38.37 
38.46 
38.56 
38.65 
38.75 


46.46 
46.66 
46.67 
46.78 
46 89 


39.18 
39.29 
39.39 
39.49 
39.59 


47.40 
47.51 
47.63 
47.74 
47.85 


40.05 
40.16 
40.27 
40.37 
40.48 


48.37 
48.49 
48.60 
48.72 
48.84 


40.97 
41.08 
41.18 
41.29 
41.40 


78.0 

78.1 
78.2 
78.3 

78.4 


38.06 
38.15 
38.24 
38.33 
38.43 


46.07 
46.17 
46.28 
46.39 
46.50 


38.84 
38.93 
39.03 
39.13 
39.23 


47.00 
47.11 
47.22 
47.34 
47.46 


39.69 
39.80 
39.90 
40.00 

40.11 


47.97 
48.08 
48.19 
48.31 
48.42 


40.59 
40.69 
40.80 
40.90 
41.01 


48.96 
49.07 
49.19 
49.31 
49.42 


41.51 

41.62 
41.73 

41.84 

41.95 


78.5 
78.6 
78.7 
78.8 
78.9 


38.52 
38.61 
38.70 
38.80 
38.89 


46.61 
46.72 
46 83 
46 93 
47.04 


39.33 
39.43 
39.54 
39.64 
39.74 


47.56 
47.67 
47.79 

47 90 

48 01 


40.21 
40.32 
40.42 
40.53 
40.63 


48 63 
48.66 
48.76 
48.88 
48.99 


41.12 
41.22 
41.33 
41.44 
41.54 


49.64 
49.66 
49.77 
49.89 
60.01 


42.05 
42.16 
42.27 
42.38 
42.49 


79.0 
79.1 
79.2 
79.3 
79.4 


38.98 
39.08 
39.18 
39.28 
39.38 


47.15 
47.26 
47.37 
47.48 
47.59 


39.84 
39.94 
40.04 
40.14 
40.24 


48.12 
48.23 
48 34 
48.46 
48.57 


40.74 
40.84 
40.95 

41.05 
41.16 


49.10 
49.22 
49.33 
49.46 
49.56 


41.65 
41.76 
41.86 
41.97 
42.08 


50.13 
50.24 
60.36 
60.48 
50.69 


42.60 
42.71 
42.82 
42.93 
43.04 


79.5 
79.6 
79.7 
79.8 
79.9 


39.48 


47.70 


40.35 


48.68 


41.26 


49.68 


42.18 


50.71 


43.15 


80.0 



236 METHODS OF ANALYSIS [Chap. 

GLYCEROL IN DRY WINES. 

7 Method I. {By Direct Weighing) — Tentative. 

Evaporate 100 cc. of the wine in a porcelain dish on a water bath to a volume 
of about 10 cc. and treat the residue with about 5 grams of fine sand and 4-5 cc. of 
milk of lime (containing about 15% of calcium oxid) for each gram of extract pres- 
ent and evaporate almost to dryness. Treat the moist residue with 50 cc. of 90% 
alcohol by volume, remove the substance adhering to the sides of the dish with a 
spatula and rub the whole mass to a paste. Heat the mixture on a water bath, 
with constant stirring, to incipient boiling and decant the liquid through a filter 
into a small flask. Wash the residue repeatedly by decantation with 10 cc. portions 
of hot 90% alcohol until the filtrate amounts to about 150 cc. Evaporate the filtrate 
to a sirupy consistency in a porcelain dish on a hot, but not boiling, water bath; 
transfer the residue to a small, glass-stoppered, graduated cylinder with 20 cc. of 
absolute alcohol and add 3 portions of 10 cc. each of anhydrous ether, shaking 
thoroughly after each addition. Let stand until clear, then pour off through a 
filter, and wash the cylinder and filter with a mixture of 1 part of absolute alcohol 
to 1| parts of anhydrous ether, also pouring the wash liquor through the filter. 
Evaporate the filtrate to a sirupy consistency, dry for an hour at the temperature 
of boiling water, weigh, ignite and weigh again. The loss on ignition gives the 
weight of glycerol. 

8 Method II. (By Oxidation ivith Dichromate) — Tentative. 

Evaporate 100 cc. of the wine in a porcelain dish on a water bath, the temperature 
of which is maintained at 85°-90°C., to a volume of 10 cc. and treat the residue with 
about 5 grams of fine sand and 5 cc. of milk of lime (containing the equivalent of 
15 grams of calcium oxid). Proceed from this point as directed under XIX, 6, be- 
ginning with the clause "evaporate almost to dryness, with frequent stirring". 
Observe the precautions given concerning the temperature at which all evapora- 
tions are to be made. 

9 GLYCEROL IN SWEET WINES.— TENTATIVE. 

With wines whose extract exceeds 5 grams per 100 cc, heat 100 cc. to boiling in 
a flask and treat with successive small portions of milk of lime until the wine be- 
comes first darker and then lighter in color. Cool, add 200 cc. of 95% alcohol by 
volume, allow the precipitate to subside, filter and wash with 95% alcohol. Treat 
the combined filtrate and washings as directed in 7 or 8. 

10 GLYCEROL-ALCOHOL RATIO.— TENTATIVE. 

Express this ratio as x : 100, in which x is obtained by multiplying the percentage 
by weight of glycerol by 100 and dividing the result by the percentage of alcohol 
by weight. 

EXTRACT. 

11 From the Specific Gravity of the Dealcoholized Wine.— Tentatire. 

Calculate the specific gravity of the dealcoholized wine by the following formula: 

S = G -i- 1 - A in which 

S = specific gravity of the dealcoholized wine; 
G = specific gravity of the wine, 3; and 

A = specific gravity of the distillate obtained in the determination of alco- 
hol, 4 (a). 



XVI] WINES 237 

From IX, 9, ascertain the per cent by weight of extract in the dealcoholized wine 
corresponding to the value of S. Multiply the figure thus obtained by the value of 
S to obtain the grams of extract per 100 cc. of wine. 

■|2 By Evaporation.— Tentative. 

(a) In dry wines, having an extract content of less than 3 grams per 100 cc. — Evapo- 
rate 50 cc. of the sample on a water bath to a sirupy consistency in a 75 cc. flat- 
bottomed platinum dish, approximately 85 mm. in diameter. Heat the residue 
for 2^ hours in a drying oven at the temperature of boiling water, cool in a desicca- 
tor and weigh as soon as the dish and contents reach room temperature. 

(b) In sweet wines. — When the extract content is between 3 and 6 grams per 100 cc, 
treat 25 cc. of the sample as directed under (a). 

When the extract exceeds 6 grams per 100 cc, however, the result, obtained as 
directed under 11, is accepted and no gravimetric determination is attempted. 
This is because of the serious error connected with drying levulose at high tempera- 
ture. 

13 NON-SUGAR SOLIDS.— TENTATIVE. 

Determine the non-sugar solids (sugar-free extract) by subtracting the amount 
of reducing sugars before inversion, 14, from the extract, 11 or 12. If sucrose is 
present in the wine, determine the non-sugar solids by subtracting the sum of re- 
ducing sugars before inversion and the sucrose from the extract. 

14 REDUCING SUGARS.— TENTATIVE. 

(a) Dry wines. — Place 200 cc. of the wine in a porcelain dish, exactly neutralize 
with N/1 sodium hydroxid, calculating the amount required from the determina- 
tion of acidity, 25, and evaporate to about one fourth the original volume. Trans- 
fer to a 200 cc. flask, add sufficient neutral lead acetate solution to clarify, dilute 
to the mark with water, shake and filter through a folded filter. Remove the lead 
with dry potassium oxalate and determine reducing sugars as directed under VIII, 

25. 

(b) Sweet wines. — In the case of sweet wines approximate the sugar content 
by subtracting 2 from the result in the determination of the extract and employ 
such a quantity of the sample that the aliquot taken for the copper reduction shall 
not exceed 245 mg. of invert sugar. Proceed as directed in (a) except that this smaller 
quantity of the sample is taken for the determination. 

SUCROSE. 

15 By Reducing Sugars Before and After Inversion. — Tentative. 

Proceed as directed under VIII, 1 8, using the method given under VIII, 25, for 

the determination of reducing sugars. 

16 By Polarization. — Tentative. 

Polarize part of the filtrate, obtained in 14, before and after inversion in 
a 200 mm. tube as directed under VIII, 14 or 16. In calculating the percentage 
of sucrose the relation of the amount of sample contained in 100 cc. to the normal 
weight must be taken into consideration. 

17 COMMERCIAL GLUCOSE.— TENTATIVE. 

Polarize a portion of the filtrate, obtained in 14, after inversion in a 200 
mm. jacketed tube at 87°C. as directed under IX, 25. In calculating the per- 



238 METHODS OF ANALYSIS [Chap. 

centage of glucose the relation of the amount of sample contained in 100 cc. to the 
normal weight for the instrument must be taken into consideration. 

1 8 ASH.— TENTATIVE. 

Proceed as directed under VIII, 4, employing the residue from 50 cc. of the wine. 

19 ASH-EXTRACT RATIO.— TENTATIVE. 

Express results as 1 : x, in which x is the quotient obtained by dividing the 
grams of extract per 100 cc. by the grams of ash per 100 cc. 

20 ALKALINITY OF THE WATER-SOLUBLE ASH.— TENTATIVE. 

Extract the ash, obtained as directed under 18, with successive small portions 
of hot water until the filtrate amounts to about 60 cc. and proceed as directed under 
IX, 18. Express the alkalinity in terms of the number of cc. of N/10 acid required 
to neutralize the water-soluble ash from 100 cc. of the wine. 

21 ALKALINITY OF THE WATER-INSOLUBLE ASH.— TENTATIVE. 

Ignite the filter and residue from 20 in the platinum dish in which the wine was 
ashed, and proceed as directed under IX, 19. Express the alkalinity in terms of 
the number of cc. of N/10 acid required to neutralize the water-insoluble ash from 
100 cc. of the wine. 

22 PHOSPHORIC ACID.-TENTATIVE. 

Dissolve the ash, obtained as directed under 18, in 50 cc. of boiling nitric acid 
(1 to 9), filter, wash the filter and determine phosphoric acid in the combined filtrate 
and washings, as directed in I, 8 or 9. If the ash ignites without difficulty, no free 
phosphoric acid need be suspected. Should there be any free acid, the ash remains 
black even after repeated leaching. In such cases calcium acetate or a mixture 
containing 3 parts of sodium carbonate and 1 of sodium nitrate should be added 
to avoid loss of phosphoric acid before attempting to ash. 

23 SULPHURIC ACID.-TENTATIVE. 

Precipitate directly the sulphuric acid in 50 cc. of the wine by means of barium 
chlorid solution, after acidifying with a small excess of hydrochloric acid, and de- 
termine the resulting barium sulphate as directed under II, 20. Allow the precipi- 
tate to stand for at least 6 hours before filtering. Report as sulphur trioxid (SOs). 

24 CHLORIN.— TENTATIVE. 

To 100 cc. of dry wine or 50 cc. of sweet wine add sufficient sodium carbonate 
to make distinctly alkaline. Evaporate to dryness, ignite at a heat not above low 
redness, cool, extract the residue with hot water, acidify the water extract with 
nitric acid and determine chlorin as directed under III, 15. 

25 TOTAL ACIDS.-TENTATIVE. 

Measure 20 cc. of the wine into a 250 cc. beaker, heat rapidly to incipient boiling 
and immediately titrate with N/10 sodium hydroxid. Determine the end point with 
neutral 0.05% azolitmin solution as an outside indicator. Place the indicator in 
the cavities of a spot plate and spot the wine into the azolitmin solution. The end 
point is reached when the color of the indicator remains unchanged by the addition 
of a few drops of N/10 alkali to the wine. 



XVI] 



WINES 



239 



In the case of wines which are artificially colored and which cannot be satis- 
factorily titrated in the above manner, it will be found helpful to use phenolphthalein 
powder (1 part of phenolphthalein mixed with 100 parts of dry, powdered potassium 
sulphate) as an indicator. Place this indicator in the cavities of a spot plate and 
spot the wine into the powder. The end of the titration is indicated when the pow- 
der acquires a pink tint. 

Express the result in terms of tartaric acid. One cc. of N/10 sodium hydroxid 
is equivalent to 0.0075 gram of tartaric acid. 



26 



VOLATILE ACIDS. 
Method I. — Tentative. 



Heat rapidly to incipient boiling 50 cc. of the wine in a 500 cc. distillation flask 
and pass steam through until 15 cc. of the distillate require only 2 drops of N/10 
sodium hydroxid for neutralization. The water used to generate the steam should 
be boiled several minutes before connecting the steam generator with the distilla- 
tion flask in order to expel carbon dioxid. Titrate rapidly with N/10 sodium hy- 
droxid, using phenolphthalein as an indicator. The color should remain about 10 
seconds. Express the result as acetic acid. One cc. of N/10 sodium hydroxid is 
equivalent to 0.0060 gram of acetic acid. 



27 



Method II. {Hortvet Method^)— Tentative. 




FIG. 8. APPARATUS FOR THE DETERMINATION OF VOLATILE ACIDS. 



Introduce 10 cc. of the wine, previously freed from carbon dioxid, into the inner 
tube of a modified Sellier distillation apparatus (Fig. 8), add a small piece of paraf- 
fin to prevent foaming, and adjust the tube and its contents in place within the larger 
flask containing 100 cc. of recently boiled water. Connect with a condenser as il- 
lustrated in Fig. 8 and distil by heating the outer flask. When 50 cc. of the distillate 
have been collected, empty the receiver into a beaker and titrate with N/10 sodium 
hydroxid, using phenolphthalein as an indicator. Continue the distillation and 
titrate each succeeding 10 cc. of distillate until not more than 1 drop of standard 
alkali is required to reach the neutral point. Usually 80 cc. of distillate will con- 
tain all the volatile acid. 



240 METHODS OF ANALYSIS [Chap. 

28 FIXED ACIDS.— TENTATIVE. 

Multiply the amount of volatile acids by 1.25 and subtract this from the total 
acids, to obtain the amount of fixed acids, expressed as tartaric acid. 

29 TOTAL TARTARIC ACID*.-TENTATIVE. 

Neutralize 100 cc. of the wine with N/1 sodium hydroxid, calculating from the 
acidity, 25, the number of cc. of N/1 alkali necessary for the neutralization. If the 
volume of the solution is increased more than 10% by the addition of the alkali, 
evaporate to approximately 100 cc. Add to the neutralized solution 0.075 gram 
of tartaric acid for each cc. of N/1 alkali added and, after the tartaric acid has dis- 
solved, add 2 cc. of glacial acetic acid and 15 grams of potassium chlorid. After 
the potassium chlorid has dissolved, add 15 cc. of 95% alcohol by volume, stir 
vigorously until the potassium bitartrate starts to precipitate, and then let stand 
in an ice box for at least 15 hours. Decant the liquid from the separated potassium 
bitartrate on a Gooch, prepared with a very thin film of asbestos, or on filter paper 
in a Biichner funnel. Wash the precipitate and filter 3 times with a few cc. of a 
mixture of 15 grams of potassium chlorid, 20 cc. of 95% alcohol by volume and 100 
cc. of water, using not more than 20 cc. of the wash solution in all. Transfer the 
asbestos or paper and precipitate to the beaker in which the precipitation was 
made, wash out the Gooch or Biichner funnel with hot water, using about 50 cc. in 
all, heat to boiling and titrate the hot solution with N/10 sodimn hydroxid, using 
phenolphthalein as an indicator. Increase the number of cc. of N/10 alkali re- 
quired by 1.5 cc. to allow for the solubility of the precipitate. One cc. of N/10 alkali 
is equivalent, under these conditions, to 0.015 gram of tartaric acid. Subtract the 
amount of tartaric acid added from this result to obtain the grams of total tartaric 
acid per 100 cc. of the wine. 

30 FREE TARTARIC ACID AND CREAM OF TARTAR^— TENTATIVE. 

Calculate the free tartaric acid and cream of tartar in the following manner: 

Let A = total tartaric acid in 100 cc. of wine divided by 0.015; 
B = total alkalinity of the ash (sum of C and D); 
C = alkalinity of water-soluble ash; 
D = alkalinity of water-insoluble ash. 
Then 

(1) If A is greater than B, 

Cream of tartar = 0.0188 X C; and 
Free tartaric acid = 0.015 X (A-B). 

(2) If A equals B or is smaller than B but greater than C, 

Cream of tartar = 0.0188 X C; and 
Free tartaric acid = 0. 

(3) If A is smaller than C, 

Cream of tartar = 0.0188 X A; and 
Free tartaric acid = 0. 



TANNIN AND COLORING MATTER.— OFFICIAL. 



31 



REAGENTS. 

(a) N/10 oxalic acid. — One cc. is equivalent to 0.004157 gram of tannin, ^k' '■ 
(D) Standard potassium permanganate solution. — Dissolve 1.333 grams of potas- 
siiun permanganate in 1 liter of water and standardize the solution against (a). 



XVI] WINES 241 

(C) Indigo solution. — Dissolve 6 grams of sodium sulphindigotate in 500 cc. of 
water by heating; cool, add 50 cc. of concentrated sulphuric acid, make up to 1 
liter and filter. 

(d) Purified boneblack^. — Boil 100 grams of finely powdered boneblack with suc- 
cessive portions of hydrochloric acid (1 to 3), filter and wash with boiling water until 
free from chlorin. Keep covered with water. 

32 DETERMINATION^. 

Dealcoholize 100 cc. of the wine by evaporation and dilute with water to the 
original volume. Transfer 10 cc. to a 2 liter porcelain dish; add about a liter of 
water and exactly 20 cc. of the indigo solution. Add the standard potassium 
permanganate solution, 1 cc. at a time, until the blue color changes to green; then add 
a few drops at a time until the color becomes golden yellow. Designate the number 
of cc. of permanganate solution used as "a". 

Treat 10 cc. of the dealcoholized wine, prepared as above, with boneblack for 
15 minutes; filter and wash the boneblack thoroughly with water. Add a liter of 
water and 20 cc. of the indigo solution and titrate with permanganate as above. 
Designate the number of cc. of permanganate used as "b". 

Then a — b = c, the number of cc. of the permanganate solution required for the 
oxidation of the tannin and coloring matter in 10 cc. of the wine. 

33 CRUDE PROTEIN.— TENTATIVE. 

Determine nitrogen in 50 cc. of the wine, as directed under I, 1 8, 21 or 23, and 
multiply the result by 6.25. 

34 PENTOSANS.— TENTATIVE. 

Proceed as directed in VIII, 64, except that 100 cc. of the wine and 43 cc. of hy- 
drochloric acid (sp. gr. 1.19) are used in beginning the distillation. Owing to the 
interference of sugars this determination can be made in dry wines only. 

35 GUM AND DEXTRIN.— TENTATIVE. 

Evaporate 100 cc. of the wine to about 10 cc. and add 10 cc. of 96% alcohol by 
volume. If gum or dextrin be present (indicated by the formation of a volximinous 
precipitate), continue the addition of alcohol, slowly and with stirring, until 100 
cc. have been added. Let stand overnight, filter, and wash with 80% alcohol by 
volume. Dissolve the precipitate on the paper with hot water, hydrolyze the 
filtrate and washings with hydrochloric acid and proceed as directed under VIII, 60. 

36 NITRATES.— TENTATIVE. 

(a) White wine. — Treat a few drops of the wine in a porcelain dish with 2-3 cc. 
of concentrated sulphuric acid, which contains about 0.1 gram of diphenylamin* 
per 100 cc. The deep blue color formed in the presence of nitrates appears so quickly 
that it is not obscured, even in sweet wine, by the blackening produced by the ac- 
tion of sulphuric acid on the sugar. 

(b) Red wine. — Clarify with basic lead acetate, filter, remove the excess of lead 
from the filtrate with sodium sulphate, filter again and treat a few drops of this 
filtrate as directed under (a). 

37 COLORING MATTERS.— TENTATIVE. 
Proceed as directed under XI. 



242 METHODS OF ANALYSIS 

38 PRESERVATIVES.— TENTATIVE. 

Proceed as directed under X. 

The detection of added boric acid is somewhat difficult because a small amount 
of it is normally present in certain wines. Therefore, a quantitative determina- 
tion should be made. The determination of sulphurous acid must also be quanti- 
tative. A small amount of salicylic acid is also normal in wine, and for that reason 
not more than 50 cc. of the sample should be used in testing for that preservative. 

BIBLIOGRAPHY. 

» U. S. Bur. Standards Bull. 9, No. 3. (Reprint 197). 

2 J. Russ. Phys. Chem. Soc, 1908, 40: 107. 

» J. Ind. Eng. Chem., 1909, 1: 31. 

< U. S. Bur. Chem. Bull. 162, p. 72. 

* Ibid., p. 75. 

6 U. S. P., VIII, 1907, p. 89. 

"> Ann. Oenologie, 1871-72, 2: 1. 

"Arch. Hyg., 1884, 2: 273. 



XVII. DISTILLED LIQUORS. 

1 SPECIFIC GRAVITY.— TENTATIVE. 

20°C 
Determine the specific gravity at -^r^ by means of a pycnometer or a small, 

accurately graduated hydrometer. 

2 ALCOHOL BY WEIGHT.— OFFICIAL. 

Weigh 20-25 grams of the sample into a distillation flask, dilute with 100 cc. of 
water, distil nearly 100 cc. and weigh the distillate or make to volume at 20°C. and 
in either case, determine the specific gravity as directed under 1 . Obtain the corre- 
sponding percentage of alcohol by weight from XVI, 5, multiply this figure by the 
weight of the distillate, and divide by the weight of the sample taken to obtain the 
per cent of alcohol by weight. 

The alcohol content of the distillate may be checked by determining the immer- 
sion refractometer reading and obtaining, from XVI, 6, the percentage of alcohol. 

ALCOHOL BY VOLUME. 

3 Method I. — Official. 

From the specific gravity of the distillate, obtained under 2, ascertain the cor- 
responding percentage of alcohol by volume from XVI, 5. Multiply this figure by 
the volume of distillate and divide by the volume of the sample (calculated from 
the specific gravity) to obtain the percentage of alcohol by volume in the original 
sample. 

4 Method II. — Tentative. 

Measure 25 cc. of the sample at 20°C. into a distillation flask, dilute with 100 
cc. of water, distil nearly 100 cc, make to volume at 20°C. and determine the spe- 
cific gravity as directed in 1 . Obtain, from XVI, 5, the corresponding percentage 
of alcohol by volume in the distillate. Multiply by 4 to obtain the percentage of 
alcohol by volume in the original substance. 

The alcohol content of the distillate may be checked by determining the immer- 
sion refractometer reading and obtaining the percentage of alcohol from XVI, 6. 

5 EXTRACT.— OFFICIAL. 

Weigh, or measure at 20°C., 100 cc. of the sample, evaporate nearly to dryness 
on the water bath, then transfer to a water oven, and dry at the temperature of 
boiling water for 2§ hours. 

6 ASH.— OFFICIAL. 

Proceed as directed under VIII, 4, employing the residue from the determination 
of the extract, 5. 

7 ACIDITY.-TENTATIVE. 

Titrate 100 cc. of the sample (or 50 cc. diluted to 100 cc. if the sample is dark) 
with N/IO alkali, using phenolphthalein as an indicator. Express the result as 
acetic acid; 1 cc. of N/10 alkali is equivalent to 0.0060 gram of acetic acid. 

243 



244 METHODS OF ANALYSIS [Chap. 

8 ESTERS.— TENTATIVE. 

Measure 200 cc. of the sample into a distillation flask, add 25 cc. of water and 
distil slowly 200 cc, using a mercury valve to prevent loss of alcohol. Exactly 
neutralize the free acid in 50 cc. of the distillate with N/10 alkali, add a measured 
excess of 25-50 cc. of N/10 alkali, and either boil for an hour under a reflux con- 
denser, cool and titrate with N/10 acid, or allow the solution to stand overnight 
in a stoppered flask with the excess of alkali, heat with a tube condenser for 30 min- 
utes at a temperature below the boiling point, cool and titrate. Calculate the 
number of cc. of N/10 alkali used in the saponification of the esters as ethyl acetate; 
1 cc. of N/10 alkali is equivalent to O.OOSS gram of ethyl acetate. Run a blank using 
water in place of the distillate and make any necessary correction. 

ALDEHYDES.— TENTATIVE. 

9 REAGENTS. 

(a) Aldehyde-free alcohol. — Redistil 95% alcohol over sodium or potassium hy- 
droxid, then add 2-3 grams per liter of meta-phenylendiamin hydrochlorid, digest 
at ordinary temperature for several days (or reflux on a steam bath for several 
hours) and then distil slowly, rejecting the first 100 cc. and the last 200 cc. of the 
distillate. 

(b) Sulphite-fttchsin solution. — Dissolve 0.50 gram of pure fuchsin in 500 cc. of 
water, then add 5 grams of sulphur dioxid dissolved in water, make up to 1 liter 
and allow to stand until colorless. This solution does not keep indefinitely; there- 
fore, prepare in small quantities and keep at a low temperature. 

(C) Standard acetaldehyde solution. — Prepare according to the directions of Vasey^ 
as follows : Grind aldehyde ammonia in a mortar with anhydrous ether and decant 
the ether. Repeat this operation several times, then dry the purified salt in a 
current of air and finally in vacuo over sulphuric acid. Dissolve 1.3S6 grams of this 
purified aldehyde ammonia in 50 cc. of 95^ alcohol by volume, add 22.7 cc. of 
N/1 alcoholic sulphuric acid, then make up to 100 cc. and add O.S cc. of alcohol 
for the volimie of the ammonium sulphate precipitate. Allow the mixture to stand 
overnight and filter. This solution contains 1 gram of acetaldehyde in 100 cc. and 
will retain its strength. 

The standard found most convenient for use is 2 cc. of this strong aldehyde 
solution diluted to 100 cc. with 50Sc alcohol by volume. One cc. of this solution 
is equivalent to 0.0002 gram of acetaldehj'de. This solution should be made up 
fresh every day or so, as it loses strength. 

10 DETERiUNATION. 

Determine the aldehyde in the distillate, prepared as directed under 8. Dilute 
5-10 cc. of the distillate to 50 cc. with aldehyde-free alcohol 50^ by volume, add 
25 cc. of the sulphite-fuchsin solution and allow to stand for 15 minutes at 15°C. 
The solutions and ^■eagents should be at 15°C. when they are mixed. Prepare 
standards of known strength and blanks in the same way. The comparison 
standards found most convenient for use contain 0.0001, 0.0002, 0.0004, 0.0005 and 
0.0006 gram of acetaldehyde. 

FURFURAL.— TENTATIVE. 

11 REAGENTS. 

(a) Standard furfural solution. — Dissolve 1 gram of redistilled furfural in 100 
cc. of 95% alcohol by volume. Standards are made by diluting 1 cc. of this solu- 



XVII] DISTILLED LIQUORS 245 

tion to 100 cc. with 50% alcohol by volume. One cc. of this solution contains 
0.0001 gram of furfural. 

(b) Furfural-free alcohol. — Prepare as directed in 9 (a). 

1 2 DETERMINATION. 

Dilute 10-20 cc. of the distillate, as prepared under 8, to 50 cc. with furfural- 
free alcohol, 50% by volume. Add 2 cc. of colorless anilin and 0.5 cc. of hydro- 
chloric acid (sp. gr. 1.125) and keep for 15 minutes in a water bath at about 15°C. 
Prepare standards of known strength and blanks in the same way. The compari- 
son standards found most convenient for use contain 0.00005, 0.0001, 0.00015, 0.0002, 
0.00025 and 0.0003 gram of furfural. 

FUSEL OIL.— TENTATIVE. 

13 REAGENTS. 

(a) Purified carbon tetrachlorid. — Mix crude carbon tetrachlorid with one tenth 
its volume of concentrated sulphuric acid, shake thoroughly at frequent intervals 
and allow to stand overnight. Wash free of acid and impurities with tap water. 
Remove the water, add an excess of sodium hydroxid solution and distil the carbon 
tetrachlorid from it. 

(b) Oxidizing solution. — Disssolve 100 grams of potassium dichromate in 900 cc. 
of water and add 100 cc. of concentrated sulphuric acid. 

14 DETERMINATION. 

(1) To 100 cc. of the sample add 20 cc. of N/2 sodium hydroxid and saponify the 
mixture by boiling for an hour under a reflux condenser; or, (2) Mix 100 cc. of the 
liqiior with 20 cc. of N/2 sodium hydroxid, allow to stand overnight at room tem- 
perature and distil directly. Connect the flask with a distillation apparatus, distil 
90 cc, add 25 cc. of water and continue the distillation until an additional 25 cc. are 
collected. 

Whenever aldehydes are present in excess of 15 parts per 100,000, add to the dis- 
tillate 0.5 gram of meta-phcuylendiamin hydrochlorid, reflux for an hour, distil 
100 cc, add 25 cc of water and continue the distillation until an additional 25 cc. 
are collected. 

Approximately saturate the distillate with finely ground sodium chlorid and add 
saturated sodium chlorid solution until the specific gravity is 1.10. 

Extract this salt solution 4 times with the purified carbon tetrachlorid, using 40, 
30, 20 and 10 cc, respectively, and wash the carbon tetrachlorid 3 times with 50 
cc. portions of saturated sodium chlorid solution, and twice with saturated sodium 
sulphate solution. Then transfer the carbon tetrachlorid to a flask containing 50 
cc. of the oxidizing solution and boil for 8 hours under a reflux condenser. 

Add 30 cc. of water and distil until only about 20 cc. remain; add 80 cc. of water 
and again distil until 15-20 cc are left. Neutralize the distillate to methyl orange, 
and titrate with N/10 sodium hydroxid, using phenolphthalein as an indicator. 
If the distillations have been properly conducted, the distillate will not show a 
marked acid reaction to methyl orange. Should considerably more than 1 cc. of 
N/10 alkali be consumed at this point, the result will be unreliable and the deter- 
mination should be repeated. One cc. of N/10 sodium hydroxid is equivalent to 
0.0088 gram of amyl alcohol. 

Rubber stoppers can be used in the saponification and first distillation, but 
corks covered with tinfoil must be used in the oxidation and second distillation. 
Corks and tinfoil must be renewed frequently. 



246 METHODS OF ANALYSIS [Chap. 

Conduct a blank determination upon 100 cc. of carbon tetrachlorid beginning 
the blank at that point of the procedure immediately after the extraction and just 
before the washings with sodium chlorid and sodium sulphate solutions. 

15 SUGARS.— TENTATIVE. 
Proceed as directed under XVI, 15, 16 or 17. 

METHYL ALCOHOL. 

16 Trillat Method^.— Tentative. 

To 50 cc. of the sample add 50 cc. of water and 8 grams of lime and fractionate 
by the aid of Glinsky bulb tubes. Dilute the first 15 cc. of the distillate to 150 cc, 
mix with 15 grams of potassium dichromate and 70 cc. of sulphuric acid (1 to 5), 
and allow to stand for an hour with occasional shaking. =• 

Distil, reject the first 25 cc. and collect 100 cc. Mix 50 cc. of the distillate with 
1 cc. of redistilled dimethylanilin, transfer to a stout, tightly stoppered flask, and 
keep on a bath at 70°-80°C. for 3 hours with occasional shaking. Make distinctly 
alkaline with sodium hydroxid solution, and distil off the excess of dimethylanilin, 
stopping the distillation when 25 cc. have passed over. 

Acidify the residue in the flask with acetic acid, shake and test a few cc. by add- 
ing 4 or 5 drops of 1% suspension of lead dioxid. If methyl alcohol is present, a 
blue coloration occurs which is increased by boiling. 

Ethyl alcohol thus treated yields a blue coloration changing immediately to green, 
later to yellow, and becoming colorless when boiled. 

1 7 Riche and Bardy Method". — Tentative. 

The following method for the detection of methyl alcohol in commercial spirit 
of wine depends on the formation of methylanilin violet : 

Place 10 cc. of the sample, previously redistilled over potassium carbonate if 
necessary, in a small flask with 15 grams of iodin and 2 grams of red phosphorus. 
Keep in ice water for 10-15 minutes until action has ceased. Distil off, on a water 
bath, the methyl and ethyl iodids formed into about 30 cc. of water. Wash with 
dilute alkali to eliminate free iodin. Separate the heavy, oily liquid which settles 
and transfer to a flask containing 5 cc. of anilin. If the action be too violent, place 
the flask in cold water; if too slow, stimulate by gently warming the flask. After an 
hour boil the product with water and add about 20 cc. of 15% sodium hydroxid 
solution; when the bases rise to the top as an oily layer, fill the flask up to the neck 
with water and draw them off with a pipette. Oxidize 1 cc. of the oily liquid by 
adding 10 grams of a mixture of 100 parts of clean sand, 2 of common salt, and 3 
of cupric nitrate; mix thoroughly, transfer to a glass tube, and heat to QO^C. 
for 8-10 hours. Exhaust the product with warm alcohol, filter and make up to 
100 cc. with alcohol. If the sample of spirits is pure, the liquid has a red tint, but, 
in the presence of 1% of methyl alcohol, it has a distinct violet shade; with 2.5% 
the shade is very distinct, and still more so with 5%. To detect more minute quan- 
tities of methyl alcohol, dilute 5 cc. of the colored liquid to 100 cc. with water, and 
dilute 5 cc. of this again to 400 cc. Heat the liquid thus obtained in a porcelain 
dish and immerse in it a fragment of white merino (free from sulphur) for 30 min- 
utes. If the alcohol is pure, the wool will remain white, but, if methyl alcohol ia 
present, the fiber will become violet, the depth of tint giving a fairly approximate 
indication of the proportion of methyl alcohol present. 



XVII] 



DISTILLED LIQUORS 



247 



18 Immersion Refractometer Method. (Leach and Lythgoe*) — Tentative. 

Determine by the immersion refractometer at 20°C. the refraction of the distil- 
late obtained in the determination of alcohol. If, on reference to the table under 
19, the refraction shows the percentage of alcohol agreeing with that obtained 
from the specific gravity, it may safely be assumed that no methyl alcohol is present. 
If, however, there is an appreciable amount of methyl alcohol, the low refractome- 
ter reading will at once indicate the fact. If the absence from the solution of re- 
fractive substances other than water and the alcohols is assured, this difference in 
refraction is conclusive of the presence of methyl alcohol. 

The addition of methyl alcohol to ethyl alcohol decreases the refraction in direct 
proportion to the amount present; hence the quantitative calculation is readily 
made by interpolation in the table under 19, using the figures for pure ethyl and 
methyl alcohol of the same alcoholic strength as the sample. 

Example. — The distillate has a specific gravity of 0.97080, corresponding to 
18.38% alcohol by weight, and has a refraction of 35.8 at 20°C. by the immersion 
refractometer; by interpolation in the refractometer table the readings of ethyl and 
methyl alcohol corresponding to 18.38% alcohol are 47.3 and 25.4, respectively, the 
difference being 21.9; 47.3 - 35.8 = 11.5; (11.5 -^ 21.9) 100 = 52.5, showing that 
52.5% of the total alcohol present is methyl alcohol. 



19 



Table 18. 



Scale readings of the Zeiss immersion refractometer at 20°C., corresponding to each 
per cent by weight of methyl and ethyl alcohols. 



PER 
CENT 


SCALE READINGS 


PER 
CENT 
ALCO- 
HOL 
BY 
WEIGHT 


SCALE READINGS 


PER 
CENT 
ALCO- 
HOL 
BT 
WEIGHT 


SCALE READINGS 


PER 
CENT 
ALCO- 
HOL 
BT 
WEIGHT 


SCALE READINGS 


ALCO- 
HOL 
BT 
WEIGHT 


Methyl 
alco- 
hol 


Ethyl 
alco- 
hol 


Methyl 
alco- 
hol 


Ethyl 
alco- 
hol 


Methyl 
alco- 
hol 


Ethyl 
alco- 
hol 

90.3 


Methyl 
alco- 
hol 


Ethyl 
alco- 
hol 





14.5 


14.5 


25 


29.7 


60.1 


50 


39.8 


75 


29.7 


101.0 


1 


14.8 


16.0 


26 


30.3 


61.9 


51 


39.7 


91.1 


76 


29.0 


101.0 


2 


15.4 


17.6 


27 


30.9 


63.7 


52 


39.6 


91.8 


77 


28.3 


100.9 


3 


16.0 


19.1 


28 


31.6 


65.5 


53 


39.6 


92.4 


78 


27.6 


100.9 


4 


16.6 


20.7 


29 


32.2 


67.2 


54 


39.5 


93.0 


79 


26.8 


100.8 


5 


17.2 


22.3 


30 


32.8 


69.0 


55 


39.4 


93.6 


80 


26.0 


100.7 


6 


17.8 


24.1 


31 


33.5 


70.4 


56 


39.2 


94.1 


81 


25.1 


100.6 


7 


18.4 


25.9 


32 


34.1 


71.7 


57 


39.0 


94.7 


82 


24.3 


100.5 


8 


19.0 


27.8 


33 


34.7 


73.1 


58 


38.6 


95.2 


83 


23.6 


100.4 


9 


19.6 


29.6 


34 


35.2 


74.4 


59 


38.3 


95.7 


84 


22.8 


100.3 


10 


20.2 


31.4 


35 


35.8 


75.8 


60 


37.9 


96.2 


85 


21.8 


100.1 


11 


20.8 


33.2 


36 


36.3 


76.9 


61 


37.5 


96.7 


86 


20.8 


99.8 


12 


21.4 


35.0 


37 


36.8 


78.0 


62 


37.0 


97.1 


87 


19.7 


99.5 


13 


22.0 


36.9 


38 


37.3 


79.1 


63 


36.5 


97.5 


88 


18.6 


99.2 


14 


22.6 


38.7 


39 


37.7 


80.2 


64 


36.0 


98.0 


89 


17.3 


98.9 


15 


23.2 


40.5 


40 


38.1 


81.3 


65 


35.5 


98.3 


90 


16.1 


98.6 


16 


23.9 


42.5 


41 


38.4 


82.3 


66 


35.0 


98.7 


91 


14.9 


98.3 


17 


24.5 


44.5 


42 


38.8 


83.3 


67 


34.5 


99.1 


92 


13.7 


97.8 


18 


25.2 


46.5 


43 


39.2 


84.2 


68 


34.0 


99.4 


93 


12.4 


97.2 


19 


25.8 


48.5 


44 


39.3 


85.2 


69 


33.5 


99.7 


94 


11.0 


96.4 


20 


26.5 


50.5 


45 


39.4 


86.2 


70 


33.0 


100.0 


95 


9.6 


95.7 


21 


27.1 


52.4 


46 


39.5 


87.0 


71 


32.3 


100.2 


96 


8.2 


94.9 


22 


27.8 


54.3 


47 


39.6 


87.8 


72 


31.7 


100.4 


97 


6.7 


94.0 


23 


28.4 


56.3 


48 


39.7 


88.7 


73 


31.1 


100.6 


98 


3.5 


93.0 


24 


29.1 


58.2 


49 


39.8 


89.5 


74 


30.4 


100.8 


99 
100 


3.5 
2.0 


92.0 
91.0 























248 METHODS OF ANALYSIS 

20 COLORING MATTERS.-TENTATIVE. 

Proceed as directed under XI. 

21 WATER-INSOLUBLE COLOR IN WfflSKIES.— TENTATIVE. 

Evaporate 50 cc. of the sample just to dryness on a steam bath. Take up with 
cold water, using approximately 15 cc, filter and wash until the filtrate amounts 
to nearly 25 cc. To this filtrate add 25 cc. of absolute alcohol, or 26.3 cc. of 95% 
alcohol by volume, and make up to 50 cc. by the addition of water. Mix thor- 
oughly and compare in a colorimeter with the original material. Calculate from 
these readings the per cent of color insoluble in water. 

COLORS INSOLUBLE IN AMYL ALCOHOL. 

22 Modified Marnh Method.—Tentative. 

Evaporate 50 cc. of whisky just to dryness on a steam bath. Dissolve the 
residue in water and 95% alcohol by volume and make to a volume of 50 cc, using 
a total volume of 2G.3 cc. of 95% alcohol. Place 25 cc. of this solution in a separatory 
funnel and add 20 cc of freshly shaken Marsh reagent (100 cc of pure amyl alco- 
hol, 3 cc. of sirupy phosphoric acid and 3 cc. of waterj, shaking lightly so as not to 
form an emulsion. Allow the layers to separate and repeat this shaking and stand- 
ing twice again. After the layers have separated completely draw off the lower 
or aqueous layer, which contains the caramel, into a 25 cc. cylinder and make up 
to volume with 50% alcohol by volume. Compare this solution in a colorimeter 
with the untreated 25 cc. Calculate the result of this reading to the per cent of 
color insoluble in amyl alcohol. 

CARAMEL. 

23 Amthor Test Modified by Lasche^. — Tentative. 

Add 10 cc. of paraldehyde to 5 cc. of the sample in a test tube and shake. Add 
absolute alcohol, a few drops at a time, shaking after each addition until the mixture 
becomes clear. Allow to stand. Turbidity after 10 minutes is an indication of 
caramel. 

BIBLIOGRAPHY. 

' Vasey. Guide to the Analysis of Potable Spirits. 1904, p. 31. 
» Abs. Analyst, 1899, 24: 13; Ibid., 211, 212. 

* Allen. Commercial Organic Analysis. 4th ed., 1909-14, 1: 98. 

* J. Am. Chem. Soc, 1905, 27: 9&4. 
'The Brewer Distiller, May, 1903. 



XVIII. BEERS. 

1 PREPARATION OF SAMPLE.— TENTATIVE. 

Remove carbon dioxid by transferring the contents of the bottle to a large flask 
and shaking vigorously or by pouring back and forth between beakers, care being 
taken that the temperature of the beer is not below 20°C. 

2 COLOR.— TENTATIVE. 

Determine the depth of color of the sample in a ? inch cell with a Lovibond tin- 
tometer, using the beer scale. Express the result in terms of a j inch cell. 

3 SPECIFIC GRAVITY.-TENTATIVE. 

20 °C 
Determine the specific gravity at ^o by means of a pycnometer. 

4 ALCOHOL.— TENTATIVE. 

Determine as directed under XVI, 4. 

EXTRACT. 

5 Method I. — Official. 

Measure 25 cc. of the carbon dioxid-free beer at 20°C. into a tared, flat-bottomed 
platinum dish, approximately 85 mm. in diameter, and evaporate just to dryness 
on a steam bath and heat to constant weight in a vacuum oven at 70°C. 

6 Method II. — Tentative. 

The immersion refractometer reading of the beer at 20°C. minus the immersion 
refractometer reading of the distillate at 20°C. times 0.2571 equals the grams of 
extract in 100 cc. of beer. 

7 Method III. — Tentative. 

Calculate the specific gravity of the dealcoholized beer by the following formula: 
S = G+ 1-A in which 

S = the specific gravity of the dealcoholized beer; 
G = the specific gravity of the beer; and 

A = the specific gravity of the distillate obtained in the determination 
of alcohol. 

From IX, 9, ascertain the per cent by weight of extract in the dealcoholized beer 
corresponding to the value of S. Multiply the figure thus obtained by S to ob- 
tain the grams of extract per 100 cc. of beer. 

8 EXTRACT OF ORIGINAL WORT (APPROXIMATE) .—TENTATIVE. 

Calculate the grams of extract per 100 cc. in the original wort by the following 
formula: 

O = 2A + E in which 

O = extract of the original wort; 

A = alcohol (grams per 100 cc); and 

E = extract of the dealcoholized beer (grams per 100 cc). 

249 



250 METHODS OF ANALYSIS [Chap. 

9 DEGREE OF FERMENTATION.— TENTATIVE. 

Calculate the degree of fermentation by the following formula: 

100 X 2A . 
U = 7^ m which 

D = degree of fermentation ; 

A = alcohol (grams per 100 cc); and 

O = extract of original wort. 

10 TOTAL ACIDS.— TENTATIVE. 

Proceed as directed under XVI, 25. Express the result as lactic acid, grams per 
100 cc. One cc. of N/10 sodium hydroxid is equivalent to 0.0090 gram of lactic 
acid. 

1 1 VOLATILE ACIDS.— TENTATIVE. 

Proceed as directed under XVI, 27. Express the result as acetic acid, grams 
per 100 cc. 

12 REDUCING SUGARS.— TENTATIVE. 

Dilute 25 cc. of the carbon dioxid-free beer, measured at 20°C., with water to 
100 cc. of the same temperature. Determine the reducing sugars in 25 cc. of this 
solution, as directed under VIII, 42. Express the result as grams of anhydrous 
maltose per 100 cc. of beer. 

1 3 DEXTRIN.— TENTATIVE , 

To 50 cc. of the carbon dioxid-free beer measured at 20°C., add 15 cc. of hydro- 
chloric acid (sp. gr. 1.125), dilute to 200 cc, attach to a reflux condenser and keep 
in a boiling water bath for 2 hours. Cool, nearly neutralize with sodium hydroxid 
solution, complete to a volume of 250 cc, filter and determine dextrose as directed 
under VIII, 52 or 54. From the number of grams of dextrose per 100 cc. of beer, 
subtract 1.053 times the amount of maltose as found in 12 and multiply the re- 
mainder by 0.9 to obtain the number of grams of dextrin per 100 cc. of beer. 

14 DIRECT POLARIZATION.— TENTATIVE. 

Read the polarization of the original sample in degrees Ventzke in a 200 mm. 
tube at 20°C. If the beer is turbid, clarify by shaking with alumina cream, filter 
and correct the reading for dilution. 

1 5 GLYCEROL.— TENTATIVE. 

Proceed as directed under XVI, 8. 

16 ASH.-OFFICIAX. 

Evaporate to dryness 25 cc. of the carbon dioxid-free sample, measured at 20°C., 
and proceed as directed under VIII, 4. 

1 7 PHOSPHORIC ACID.-TENTATIVE. 

To 25 cc of the carbon dioxid-free beer, measured at 20°C., add 20 cc. of 2% 
calcium acetate solution, evaporate to dryness and ignite at low redness to a white 
ash. Add 10-15 cc. of boiling nitric acid (1 to 9) and determine phosphoric acid 
(P2O6) as directed under I, 9. 



XVIII] BEERS 251 

■j 8 PROTEIN.— OFFICIAL. 

Measure, at 20°C., 25 cc. of the carbon dioxid-free beer into a Kjeldahl digestion 
flask, add a small amount of tannin to prevent frothing, evaporate to dryness, de- 
termine nitrogen as directed under I, 18, 21 or 23, multiply the result by 6.25 and 
calculate the percentage of protein, 

1 9 PRESERVATIVES.— TENTATIVE. 
Proceed as directed under X. 

20 COLORING MATTERS.— TENTATIVE. 
Proceed as directed under XI. 

21 METALS.— TENTATIVE. 
Proceed as directed under XII. 



XIX. VINEGARS. 

(Unless otherwise noted, express results as grams per 100 co.) 

1 PHYSICAL EXAMINATION.— TENTATIVE. 

Note the appearance, color, odor and taste. 

2 PREPARATION OF SAMPLE.— TENTATIVE. 

If the sample is turbid, filter before proceeding with the analysis. 

3 SPECIFIC GRAVITY.— TENTATIVE. 

20 °C 
Determine the specific gravity at -^ by means of a pycnometer. 

4 ALCOHOL.— TENTATIVE. 

Measure 100 cc. of the sample into a round-bottomed, distillation flask. Make 
faintly alkaline with saturated sodium hydroxid solution, add a small piece of 
paraffin, distil almost 50 cc, make up to 50 cc. at the temperature of the sample 

20°C 

and determine the specific gravity at -p— ' by means of a pycnometer. Obtain from 
XVI, 5, the per cent by volume, or grams per 100 cc, noting that the alcoholic 
strength of the distillate is twice that of the original vinegar. 

GLYCEROL.— TENTATIVE. 

5 BEAOENTS. 

(a) Strong potassium dichromate solution. — Dissolve 74.56 grams of dry, recrystal- 
lized potassium dichromate in water, add 150 cc. of concentrated sulphuric acid, 
cool and make up to 1 liter at 20°C. One cc. of this solution is equivalent to 0.01 
gram of glycerol. The high coefficient of expansion of this strong solution necessi- 
tates its preparation at exactly 20°C. and the measurement of any definite volume 
at the same temperature. If desired, the measurements may be made at room 
temperature by means of a weighing burette, the volume used in this case being 

ascertained by dividing the weight of the solution used by its specific gravity at 

20 °C. 

4° 

(b) Dilute potassium dichromate solution. — Measure 25 cc. of the strong potas- 
sium dichromate solution at exactly 20°C. into a 500 cc. volumetric flask, dilute with 
water and make up to the mark at room temperature. Twenty cc. of this solution 
are equivalent to 1 cc. of (a). 

(C) Ferrous ammonium sulphate solution. — Dissolve 30 grams of crystallized fer- 
rous ammonium sulphate in water, add 50 cc. of concentrated sulphuric acid, cool 
and dilute at room temperature. One cc. of this solution is approximately equiva- 
lent to 1 cc. of (b). Its value changes slightly from day to day and it must be 
standardized against (b) whenever used. 

(d) Potassium ferricyanid indicator. — Dissolve 1 gram of crystallized potassium 
ferricyanid in 50 cc. of water. This solution must be freshly prepared. 

(e) Milk of lirne. — Introduce 150 grams of calcium oxid, selected from clean, hard 
lumps, prepared preferably from marble, into a large porcelain or iron dish, slake 
with water, cool and add sufficient water to make 1 liter. 

253 



254 METHODS OF ANALYSIS [Chap. 

(f) Silver carbonate. — Dissolve 0.1 gram of silver sulphate in about 50 cc. of water, 
add an excess of sodium carbonate solution, allow the precipitate to settle and 
wash with water several times by decantation until the washings are practically 
neutral. This reagent must be freshly prepared immediately before use. 

6 DETERMINATION. 

All evaporations should be jnade on a water bath, the temperature of which is main- 
tained at 85°-90°C. 

Evaporate 100 cc. of the vinegar to 5 cc, add 20 cc. of water and again evaporate 
to 5 cc. to expel acetic acid. Treat the residue with about 5 grams of fine sand and 
15 cc. of the milk of lime and evaporate almost to dryness, with frequent stirring, 
avoiding the formation of a dry crust or evaporation to complete dryness. Treat 
the moist residue with 5 cc. of water, rub into a homogeneous paste, then add 
slowlj' 45 cc. of absolute alcohol, washing down the sides of the dish to remove 
adhering paste, and stir thoroughly. Heat the mixture on a water bath, with 
constant stirring, to incipient boiling, transfer to a suitable vessel and centrifu- 
galize. Decant the clear liquid into a porcelain dish and wash the residue with 
several small portions of hot 90% alcohol by volume by aid of the centrifuge. 
(If a centrifuge is not available, decant the liquid through a fluted filter into a 
porcelain dish. Wash the residue repeatedly with small portions of hot 90% alco- 
hol, twice by decantation, and then by transferring all the material to the filter. 
Continue the washing until the filtrate amounts to 150 cc.) Evaporate to a sirupy 
consistency, add 10 cc. of absolute alcohol to dissolve this residue and transfer to 
a 50 cc. glass-stoppered cylinder, washing the dish with successive small portions of 
absolute alcohol until the volume of the solution amounts to 20 cc. Thou add 
'3 portions of 10 cc. each of anhydrous ether, shaking thoroughly after each addi- 
tion. Let stand until clear, tiien pour otT through a filter, and wash the cylinder 
and filter with a mixture of 2 volumes of absolute alcohol and 3 of anhydrous ether. 
If a heavy precipitate has formed in the cylinder, centrifugalize at low speed, de- 
cant the clear liquid and wash 3 times with 20 cc. portions of the alcohol-ether 
mixture, shaking the mixtm-e thoroughly each time and separating the precipitate 
by means of the centrifuge. Wash the paper with the alcohol -ether mixture, and 
evaporate the filtrate and washings on the water bath to about 5 cc, add 20 cc. 
of water and again evaporate to 5 cc. ; again add 20 cc. of water and evaporate to 5 
cc; finally add 10 cc. of water and evaporate to 5 cc. 

These evaporations are necessary to remove all the ether and alcohol, and, when 
conducted at S5°-90^C., result in no loss of gh^cerol if the concentration of the latter 
is less than 50%. 

Transfer the residue with hot water to a 50 cc. graduated flask, cool, add the 
silver carbonate, prepared from 0.1 gram of silver sulphate, shake and allow to stand 
10 minutes; then add 0.5 cc of basic lead acetate solution [VIII, 13 (a)], shake 
occasionally and allow to stand 10 minutes; make up to the mark, shake well, filter, 
rejecting the first portion of the filtrate, and pipette 25 cc. of the clear filtrate into 
a 250 cc. volumetric flask. 

Add 1 cc. of concentrated sulphuric acid to precipitate the excess of lead and 
then 30 cc. of the strong potassium dichromate solution. Add carefully 24 cc. of 
concentrated sulphuric acid, rotating the flask gently to mix the contents and avoid 
violent ebullition, and then place in a boiling water bath for exactly 20 minutes. 
Remove the flask from the bath, dilute, cool and make up to the mark at room tem- 
perature. The amount of strong dichromate solution used must be sufficient to 



XIX] VINEGARS 255 

leave an excess of about 12.5 cc. at the end of the oxidation, the amount given above 
(30 cc.) being sufhcient for ordinary vinegar containing about 0.35 gram or less of 
glycerol per 100 oc. 

Standardize the ferrous ammonium sulphate solution against the dilute potas- 
sium dichromate solution by introducing from the respective burettes approxi- 
mately 20 cc. of each of the 2 solutions into a beaker containing 100 cc. of water. 
Complete the titration using the potassium ferricyanid solution as an outside indi- 
cator. From this titration calculate the volume (/'') of the ferrous ammonium sul- 
phate solution equivalent to 20 cc. of the dilute and also, therefore, to 1 cc. of the 
strong dichromate solution. 

In i)hu'e of the dilute dichromate solution, substitute a burette containing the 
oxidized glycerol with an excess of the strong dichromate solution and ascertain how 
many cc. are equivalent to {F) cc. of the ferrous anunonium sulphate solution and 
also, therefore, to 1 cc. of the strong dichromate solution. Then 250 divided by this 
last equivalent equals the number of cc. of the strong dichromate solution pres- 
ent in excess in the 250 cc. flask after oxidation of the glycerol. 

The number of cc. of the strong dichromate solution added, minus the excess 
found after oxidation, multiplied by 0.02 gives the grams of glycerol per 100 cc. of 
vinegar. 

7 SOLIDS.— TENTATIVE. 

Measure 10 cc. of the sample into a tared, flat-bottomed platinum dish of 50 
mm. bottom diameter, evaporate on a boiling water bath for 30 minutes, and dry 
for exactly 2^j hours in a water oven at the temperature of boiling water. Cool in 
a desiccator and weigh. It is essential that the size and shape of the dish and the 
time of drying be followed strictly. 

8 TOTAL REDUCING SUBSTANCES BEFORE INVERSION.— TENTATIVE. 

Proceed as directed under VIII, 25, using 10 cc. of the sam])le. In Ihe case of 
malt vinegar, express the results as dextrose; in all other cases as invert sugar. 

9 REDUCING SUGARS BEFORE INVERSION AFTER EVAPORATION.— TENTATIVE. 

Evaporate 50 cc. of the sample on the water bath to a volume of 5 cc. Add 25 
cc. of water and again evaporate to 5 cc. Transfer to a 100 cc. volumetric flask, 
make up to the mark, and proceed as directed under 8, using a quantity equivalent 
to 10 or 20 cc. of the saiuple. 

1 REDUCING SUGARS AFTER INVERSION.— TENTATIVE. 

Proceed as directed under 9. After the last evaporation to 5 cc. transfer to a 
100 cc. volumetric flask with 70 cc. of water, and invert as directed under VIII, 
14. Nearly neutralize with sodium hydroxid solution, make up to the mark and 
proceed as directed under VIII, 25, using a quantity equivalent to 10 or 20 cc. of 
the sample. 

1 1 LEAD PRECIPITATE.-TENTATIVE. 

To 10 cc. of the sample in a test tube, add 2 cc. of 20% lead acetate solution, 
shake and let stand 30 minutes. Describe the precipitate as turbid, light, normal, 
heavy or very heavy. 

1 2 POLARIZATION.— TENTATIVE. 

If the lead prcci{)itate is normal, add to 50 cc. of the sample 5 cc. of basic lead 
acetate solution [VIII, 13 (a)], shake, let stand 30 minutes, filter and polarize, 



256 METHODS OF ANALYSIS [Chap. 

preferably in a 200 mm. tube, correcting for dilution. If basic lead acetate gives 
only a turbidity, add to the sample, already treated with basic lead acetate, 10 cc. 
of alumina cream [VIII, 13 (b)], shake, let stand 30 minutes, filter and polarize, 
correcting for dilution. In the case of malt vinegar, treat 100 cc. of the sample with 
5 cc. of 10% phosphotungstic acid solution and filter. To 50 cc. of the filtrate add 
5 cc. of the basic lead acetate solution, filter and polarize, correcting the reading 
obtained for dilution. 

1 3 ASH.— TENTATIVE. 

(a) Measure 25 cc. of the vinegar into a tared platinum dish, evaporate to dry- 
ness on the steam bath and proceed as directed under VIII, 4. 

(b) Evaporate 25 cc. of the sample to dryness as directed under (a), heat in a 
muffle at low heat to expel inflammable gases, treat the charred portion with a few 
cc. of water, and evaporate to dryness on a water bath; replace in the muffle at low 
redness for 15 minutes, and continue the alternate evaporation and heating until 
a white or gray ash is obtained, at no time exceeding a dull red heat; cool in a 
desiccator and weigh. 

Useful information may often be obtained by noting the odor given off by the 
solids during charring. 

1 4 SOLUBLE AND INSOLUBLE ASH.— TENTATIVE. 
Treat the ash, obtained in 1 3, as directed under IX, 1 7. 

1 5 ALKALINITY OF THE SOLUBLE ASH.— TENTATIVE. 

Proceed as directed under IX, 18, expressing the result as the number of cc. 
of N/10 hydrochloric acid required to neutralize the soluble ash from 100 cc. of the 
vinegar. 

1 S SOLUBLE AND INSOLUBLE PHOSPHORIC ACID.- TENTATIVE. 

Determine phosphoric acid in the water-soluble and water-insoluble portions of 
the ash as directed under I, 9, dissolving the water-insoluble portion in about 
50 cc. of boiling nitric acid (1 to 9). Express the result as mg. of phosphorus 
pentoxid (P2O6) in 100 cc. of the vinegar. 

1 7 TOTAL ACIDS.— TENTATIVE. 

Dilute 10 cc. of the sample with recently boiled and cooled water until it appears 
very slightly colored, and titrate with N/2 alkali, using phenolphthalein as an 
indicator. One cc. of N/2 alkali is equivalent to 0.030 gram of acetic acid. 

1 8 FIXED ACIDS.— TENTATIVE. 

Measure 10 cc. of the vinegar into a 200 cc. porcelain casserole, evaporate just to 
dryness, add 5-10 cc. of water, and again evaporate; repeat until at least 5 evapora- 
tions have taken place. Add about 200 cc. of recently boiled and cooled water and 
titrate with N/10 alkali, using phenolphthalein as an indicator. One cc. of N/10 
alkali is equivalent to 0.0067 gram of malic acid. 

19 VOLATILE ACIDS.— TENTATIVE. 

To obtain the volatile acids subtract the fixed acids, calculated as acetic acid, 
from the total acids. 



XIX] VINEGARS 257 

20 COLOR.— TENTATIVE. 

Determine the depth of color in a Lovibond tintometer by good, reflected day- 
light, using a ^ inch cell and the brewer's scale. Express the result in terms of 
a I inch cell. 

FORMIC ACID. 

21 Fincke MethodK— Tentative. 

Employ the apparatus described under X, 39, Fig. 6. Introduce 100 cc. of the 
sample into flask (A), add 0.4-0.5 gram of tartaric acid, and place in position as 
shown in Fig. 6, the flask (B) having previously been charged with a suspension of 
15 grams of calcium carbonate in 100 cc. of water. Heat the contents of flasks (A) 
and (B) to boiling and distil with steam from the generator (S), the vapor passing 
first through the sample in flask (A), then through the boiling suspension of cal- 
cium carbonate in flask (B), after which it is condensed and measured in the re- 
ceiver (C). Maintain the volume of liquid in flask (B) as nearly constant as pos- 
sible and reduce the volume of the sample in flask (A) to 30-40 cc. by heating with 
small Bunsen flames, the distillation being continued until 1 liter of distillate is 
collected. Disconnect the apparatus, filter the calcium carbonate suspension, and 
wash the calcium carbonate that remains on the paper with a little hot water. 
Render the filtrate faintly acid with hydrochloric acid, add 10-15 cc. of mercuric 
chlorid reagent [ X, 38 (b) ], mix and heat on a boiling water bath for 2 hours. Filter 
on a tared Gooch, wash the precipitate thoroughly with cold water and finally with 
a little alcohol. Dry in a boiling water oven for 30 minutes, cool in a desiccator, 
weigh, and calculate the weight of formic acid present by multiplying the weight 
of the precipitate by 0.0975. 

22 ALCOHOL PRECIPITATE.— TENTATIVE. 

Evaporate 100 cc. of the vinegar to about 15 cc. When there is considerable 
sugar in the vinegar, if the sample is evaporated to too low a volume, a gummy or 
stringy precipitate is formed on adding the alcohol instead of a flocculent one. When 
the sugar content is high, therefore, the evaporation should not be carried beyond 
20 cc. To this residue add slowly and with constant stirring 200 cc. of 95% alcohol 
by volume and allow the mixture to stand overnight. From this point proceed 
as directed under XIII, 18, beginning with the sentence, "Filter and wash with 
80% alcohol by volume". 

23 PENTOSANS.— TENTATIVE. 

Proceed as directed in VIII, 64, except that 100 cc. of the vinegar and 43 cc. of 
hydrochloric acid (sp. gr. 1.19) are used in beginning the distillation. 

TARTARIC ACID AND TARTRATES. 

24 Qualitative Test. — Tentative. 

Evaporate 50 cc. of the vinegar in a porcelain dish to a volume of about 10 cc, 
filter into a test tube, add 1 cc. of 25% calcium chlorid solution and 2 cc. of 50% 
ammonium acetate solution and allow to stand overnight. In the presence of tar- 
taric acid a deposit of calcium tartrate is formed, the crystals of which may be 
identified under the microscope by their characteristic form. 

25 TOTAL TARTARIC ACID.— TENTATIVE. 

Evaporate 200 cc. of the sample to a sirupy consistency to remove excess of acetic 
acid, dilute to the original volume with water in a volumetric flask, determine the 



258 METHODS OF ANALYSIS 

acidity as directed in 17, and determine total tartaric acid in a 100 cc. aliquot as 
directed under XVI, 29, except that 20 cc. of alcohol are used in the precipitation 
instead of 15 cc. 

FREE MINERAL ACIDS. 

26 Logwood Method'. — Tentative. 

Prepare an extract of logwood as follows: Pour 100 cc. of boiling water upon 2 
grams of fresh logwood chips, allow the infusion to stand for a few hours and filter. 
Place drops of the liquid on a porcelain surface and dry on a water bath. Add to 
one of the spots a drop of the vinegar to be tested (after concentration if desirable) 
and evaporate to dryness. A yellow tint remains if free mineral acids are absent, 
a red tint if they are present. 

27 Methijl Violet Method. — Tentative. 

Add 5-10 cc. of water to 5 cc. of vinegar and, after mixing well, add 4 or 5 drops 
of methyl violet solution (1 part of methyl violet 2B in 10,000 parts of water). A 
blue or green coloration indicates the presence of a free mineral acid. 

28 Quantitative Method. {Hehner Method) — Tentative. 

To a measured amount of the sample add a measured excess of standard alkali, 
evaporate to dryness, incinerate and titrate the ash with standard acid, using 
methyl orange as an indicator. The difference between the number of cc. of alkali 
first added and the number of cc. of acid needed to titrate the ash represents the free 
mineral acid present. 

29 METALS.— TENTATIVE. 
Proceed as directed under XII. 

DEXTRIN. 

30 Qualitative Test. — Tentative. 

Evaporate 100 cc. of the vinegar to a volume of about 15 cc. Add slowly and 
with constant stirring 200 cc. of 95% alcohol by volume and allow to stand over- 
night. The precipitate formed should be tested for dextrin by the optical rotation 
and color reaction with iodin. 

SPICES AND ADDED PUNGENT MATERIALS. 

31 Qualitative Test. — Tentative. 

Neutralize exactly a portion of the vinegar and test by taste and smell. Agitate 
the liquid with ether in a separatory funnel, remove and evaporate the ethereal 
layer, and note the odor and taste of the residue. 

32 COLORING MATTERS.— TENTATIVE. 
Proceed as directed under XI. 

33 PRESERVATIVES.- TENTATIVE. 
Proceed as directed under X. 

BIBLIOGRAPHY. 

1 Z. Nahr. Genussm., 1911, 21: 1; 22: 88. 

=* Allen. Commercial Organic Analysis. 4th ed., 1909-14, 1: 503. 



JOURNAL 

OF THE 

ASSOCIATION OF OFFICIAL 
AGRICULTURAL CHEMISTS 



Vol. II NOVEMBER 15, 1916 No. 3 




BOARD OF EDITORS 
C. L. Albbbrq, Chairman 
R. E. DooLiTTLB J. P. Street 

E. F. Ladd L. L. Van Sly: 

PART II 

Report of Committee on Editing Methods of Analysis 

Flavoring Extracts 

Meat and Meat Products 

Dairy Products 

Fats and Oils 

Spices and other Condiments 

Cacao Products 

Coffees 

Tea 

Baking Powders and their Ingredients 

Drugs 

Index 

PUBLISHED QUARTERLY BY 

THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS 

WILLIAMS & WILKINS COMPANY 

BALTIMORE, U. S. A. 

THE CAMBRIDGE UNIVERSITY PRESS 
FETTER LANE, LONDON, E. C. 



Entered aa second-class matter August 25, 1915. at the Post-Office at Baltimore. Maryland, under the Act of August 24, 1912 
Copyright 1916 by Association of Official Agricultural Chemists 



NOV 20 1916 
S)C1.B37000''^ 



XX. FLAVORING EXTRACTS. 
VANILLA EXTRACT AND ITS SUBSTITUTES. 

"I SPECIFIC GRAVITY.— TENTATIVE. 

20''C 
Determine the specific gravity at -^' by means of a pycnometer 

2 ALCOHOL.— OFFICIAL. 
Proceed as directed under XVII, 2 or 3. 

3 GLYCEROL.— TENTATIVE. 

Proceed as directed under XVI, 7, 8 or 9, the method selected depending upon 
the amount of sugar present, employing an amount of the sample containing 0.10- 
0.40 gram of glycerol. 

VANILLIN AND COUMARIN. 
Modified Hess and Prescott Method^. — Tentative. 

(This method is not applicable to concentrated vanillin and coumarin 

preparations in which the amount of vanillin and coumarin present 

exceeds the quantity dissolved by 100 cc. of water at 20°C. 

In such cases employ a smaller amount of the sample 

and dilute to 50 cc.) 

4 PREPARATION OF SOLUTION. 

Measure 50 cc. of the extract at 20°C. into a 250 cc. beaker with marks showing 
volvunes of 80 and 50 cc, dilute to 80 cc. and evaporate to 50 cc. on a water bath kept 
at 70°C. Dilute again with water to 80 cc. and evaporate to 50 cc. Transfer to a 
100 cc. flask, rinsing the beaker with hot water; add 25 cc. of 8% lead acetate solu- 
tion; make up to the mark with water, shake and allow to stand 18 hours (over- 
night) at 37°-40°C. Decant into a small, dry filter, reserving the filtrate for the 
determination of vanillin and coumarin, the normal lead number, 6, and the 
residual color, 14. 

5 DETERMINATION. 

Transfer a 50 cc. aliquot of the filtrate to a separatory funnel and extract with 4 
successive 15 cc. portions of ether (previously washed twice with an equal volume 
of water to remove alcohol). Wash the combined ether solutions 4 or 5 times with 
2% ammonium hydroxid solution (2% NH3 by weight), using 10 cc. the first time 
and 5 cc. thereafter, and reserve the ether solution for the determination of cou- 
marin. Slightly acidify the combined ammoniacal solutions with hydrochloric 
acid ; cool and extract in a separatory funnel with 4 portions of washed ether, using 
about 40 cc. altogether. Evaporate the ethereal solutions at room temperature, 
dry over sulphuric acid and weigh. If the residue is considerably discolored or 
gummy, re-extract in the dry state with boiling petroleum ether (b. p. 40°C. or 
below) not less than 15 times; evaporate the solvent, dry and weigh. The residue 
should now be white, crystalline vanillin, with a melting point of approximately 

259 



260 METHODS OF ANALYSIS [Chap. 

80°C. A small amount of this residue, dissolved in 2 drops of concentrated hydro- 
chloric acid, should develop a pink color upon the addition of a crystal of resorcin. 
Evaporate at room temperature the original ether extract of the sample, from 
which the vanillin has been removed by means of ammonium hydroxid, and dry 
over sulphuric acid. The residue, if pure coumarin, should melt at approximately 
67°C. and should respond to Leach's test for coumarin as follows: A small por- 
tion of the residue, dissolved in not more than 0.5 cc. of hot water, should yield 
a brown precipitate upon the addition of a few drops of N/10 iodin. This pre- 
cipitate finally gathers in green flecks, leaving a clear, brown solution. The 
reaction is especially marked if the reagent is applied with a glass rod to a few 
drops of the solution on a white plate or tile. 

6 NORMAL LEAD NUMBER'.— TENTATIVE. 

To a 10 cc. aliquot of the filtrate from the lead acetate precipitate, as obtained 
in 4, add 25 cc. of water, 0.5-1.0 cc. of sulphuric acid, and 100 cc. of 95% alcohol by 
voliune. Let stand overnight, filter on a Gooch crucible, wash with 95% alcohol, 
dry at a moderate heat, ignite at low redness for 3 minutes, taking care to avoid 
the reducing flame, and weigh. Conduct a blank determination employing v/ater 
containing 4 or 5 drops of glacial acetic acid in place of the sample. The normal lead 
number is calculated by the following formula: 

P - '00X0.6831(S-W ) _ j3^^^ ^^ _ ^^, .^ ^,_.^^ 
5 

P = normal lead number (grams of metallic lead in the precipitate obtained 
from 100 cc. of the sample); 

S = grams of lead sulphate corresponding to 2.5 cc. of the lead acetate solu- 
tion as determined in a blank analysis; and 

W = grams of lead sulphate obtained in 10 cc. of the filtrate from the lead 
acetate precipitate, as obtained in 4. 

7 TOTAL SOLIDS.— TENTATIVE. 

Proceed as directed under IX, 4, employing 10 grams of the sample. 

8 ASH.— OFFICIAL. 

Evaporate 10 grams of the extract and determine the ash as directed under 

vin, 4. 

9 ASH CONSTITUENTS.— TENTATIVE. 
Proceed as directed under III or XXVIII, 21-26, inclusive. 

10 SUCROSE.-TENTATIVE. 
Determine as directed under VIII, 14 or 18. 

VANILLA RESINS. 

• I Qualitative Test. — Tentative. 

Place 50 cc. of the extract in a glass dish and evaporate the alcohol on a water 
bath. When the alcohol is removed, make up to about the original volume with 
hot water. If alkali has not been used in the manufacture of the extract, the resina 
will appear as a flocculent red to brown residue. Acidify with acetic acid to free 
the resins from the bases, separating the resins completelj^ and leaving a partly 
decolorized, clear, supernatant liquid after standing a short time. Collect the 
resins on a filter, wash with water and reserve the filtrate for further tests. 



XX] FLAVORING EXTRACTS 261 

Place a portion of the filter with the attached resins in a few cc. of dilute potas- 
sium hydroxid solution. The resins are dissolved, giving a deep red solution; 
acidify, and the resins are precipitated. 

Dissolve a portion of the resins in alcohol. To one portion add a few drops of 
ferric chlorid solution; to another portion hydrochloric acid; neither produces any 
marked change in color. Most resins, however, in alcoholic solution give color 
reactions with ferric chlorid or hydrochloric acid. 

To a portion of the filtrate obtained above add a few drops of basic lead acetate 
solution. The precipitate is so bulky as to almost solidify, due to the excessive 
amount of organic acids, gums and other extractive matter. The filtrate from 
this precipitate is almost colorless. 

Test another portion of the filtrate from the resin for tannin with a solution of 
gelatin. Tannin is present in varying but small quantities, but should not be 
present in great excess. 

"12 METHYL ALCOHOL.— TENTATIVE. 

Proceed as directed under XVII, 16, 17 or 18, using the distillate from the de- 
termination of alcohol, 2. 

1 3 COLOR VALUE.— TENTATIVE. 

Pipette 2 cc. of the extract into a 50 cc. graduated flask and make up to the mark 
with a mixture of equal parts of 95% alcohol by volume and water. Determine 
the color value of this diluted extract in terms of red and yellow by means of a 
Lovibond tintometer, using a 1 inch cell. To obtain the color value of the original 
extract, multiply the figures for each color by 25. 

14 RESIDUAL COLOR AFTER PRECIPITATION WITH LEAD ACETATE'.-TENTATIVE. 

Determine the color value, in terms of red and yellow, of the filtrate from the 
lead acetate precipitate as obtained in 4, using a 1 inch Lovibond cell. Multiply 
the reading by 2 to reduce the results to the basis of the original extract. If the 
actual reading of the solution is greater than 5 red and 15 yellow, as may happen 
if the extract is highly colored with caramel, a ^ or i inch cell should be employed, 
and the readings multiplied, respectively, by 4 or 8. Divide the figures for red and 
yellow, respectively, by the corresponding figures of the original extract and mul- 
tiply the quotients by 100, to obtain the percentages of the 2 colors remaining in 
the lead acetate filtrate. 

Calculate also the ratio of red to yellow in both extract and lead acetate filtrate. 

COLORS INSOLUBLE IN AMYL ALCOHOL. 

1 5 Modified Marsh Method. — Tentative. 

Proceed as directed under XVII, 22, using 25 cc. of the extract and shaking with 
25 cc. of the Marsh reagent instead of 20 cc. 

16 COLORING MATTERS OTHER THAN CARAMEL.— TENTATIVE. 

Proceed as directed under XI. 

LEMON AND ORANGE EXTRACTS. 

17 SPECIFIC GRAVITY.— TENTATIVE. 

Determine the specific gravity at '^-^ by means of a pycnometer. 



262 METHODS OF ANALYSIS [Chap. 

1 8 ALC OHOL.— TENTATIVE, 

Dilute 50 cc. of the extract, measured at 20°C., with water to about 200 cc, allow 
the mixture to stand until the oil separates in a clear layer at the top, or centrifugal- 
ize, then make up to the mark, using the lower meniscus of the oil. Pour the mixture 
into a dry Erlenmeyer flask containing 5 grams of light magnesium carbonate, 
stopper, shake well and filter quickly through a large, dry, folded filter. Intro- 
duce a 150 cc. aliquot of the filtrate, measured at 20°C., into a .300-500 cc. distilla- 
tion flask, attach the flask to a vertical condenser and distil almost 100 cc. Com- 
plete the volume of the distillate to 100 cc. at 20°C., mix well and determine the 

20°C 
specific gravity at -^s— ^ • Ascertain the corresponding per cent of alcohol by volume 

from XVI, 5 and multiply the result thus obtained by 2f to obtain the percentage 
of alcohol by volume in the original sample. 

19 GLYCEROL.— TENTATIVE. 
Proceed as directed under 3. 

LEMON AND ORANGE OILS. 

20 By Polarization. {Mitchell Method) — Tentative. 

Without diluting polarize the extract at 20°C. in a 200 mm. tube. Divide the 
reading in degrees Ventzke by 3.2 in the case of lemon extract and by 5.2 in the 
case of orange extract; in the absence of other optically active substances, the re- 
sult will be the percentage of oil by volume. A small amount of cane sugar is occa- 
sionally present; if so, determine as directed under 28 and correct the reading 
accordingly. 

21 By Precipitation. {Mitchell Method) — Tentative. 

Pipette 20 cc. of the extract into a Babcock milk bottle, add 1 cc. of hydrochloric 
acid (1 to 1), then 25-28 cc. of water previously warmed to 60°C., mix, let stand 
in water at 60°C. for 5 minutes, centrifugalize for 5 minutes, fill with warm water 
to bring the oil into the graduated neck of the flask, again centrifugalize for 2 min- 
utes, place the flask in water at 60°C. for a few minutes and note the per cent of oil 
by volume. If oil of lemon is present in amounts over 2%, add 0.4% to the per- 
centage of oil noted to correct for the solubility of the oil. If less than 2% and 
more than 1% is present, add 0.3% for this correction. 

When the extract is made in accordance with the U. S. P., the results by the 
methods given under 20 and 21 should agree within 0.2%. 

To obtain the per cent by weight from the per cent by volume, as found by either 
of these methods, multiply the volume percentage by 0.86 in the case of lemon ex- 
tracts, and by 0.85 in the case of orange extracts, and divide the result by the specific 
gravity of the original extract. 

TOTAL ALDEHYDES. 

Chace Method*. — Tentative. 

22 REAGENTS. 

(a) Aldehyde-free alcohol. — Allow 95% alcohol by volume, containing 5 grams 
of meta-phenylendiamin hydrochlorid per liter, to stand for 24 hours with fre- 
quent shaking. (Nothing is gained by previous treatment with potassium hy- 
droxid.) Boil under a reflux condenser for at least 8 hours, longer if necessary, 
allow to stand overnight and distil, rejecting the first 10 and the last 5 per cent 



XX] FLAVORING EXTRACTS 263 

which come over. Store in a dark, cool place in well filled bottles. Twenty-five cc. 
of this alcohol, on standing 20 minutes at 14°-16°C. with 20 cc. of the sulphite fuchsin 
solution, should develop only a faint pink coloration. If a stronger color is de- 
veloped, repeat the treatment with meta-phenylndiamin hydrochlorid as above. 

(b) Sulphite-fuchsin solution. — Dissolve 0.5 gram of fuchsin in 250 cc. of water, 
add an aqueous solution of sulphur dioxid containing 16 grams of the gas, allow to 
stand until colorless, or nearly so, and make up to 1 liter with water. Let stand 12 
hours before using and keep in a refrigerator. This solution is liable to deteriorate 
and should be reasonably fresh when used. 

(C) Standard citral solution. — Use 0.5 or 1 mg. of C.P. citral per cc. in 50% alde- 
hyde-free alcohol. 



23 



DETERMINATION. 



Weigh approximately 25 grams of the extract in a stoppered weighing flask, 
transfer to a 50 cc. flask and make up to the mark at room temperature with alde- 
hyde-free alcohol. Measure, at room temperature, 2 cc. of this solution into a 
comparison tube. Add 25 cc. of the aldehyde-free alcohol (previously cooled to 
14°-16°C.), then 20 cc. of the sulphite-fuchsin solution (also cooled) and finally make 
up to the 50 cc. mark with more aldehyde-free alcohol. Mix thoroughly, stopper 
and keep at 14°-16°C. for 15 minutes. Prepare a standard for comparison at the 
same time and in the same manner, using 2 cc. of the standard citral solution, and 
compare the colors developed. Calculate the amount of citral present and re- 
peat the determination, using a quantity sufficient to give the sample approxi- 
mately the strength of the standard. From this result calculate the amount of 
citral in the sample. If the comparisons are made in Nessler tubes, standards 
containing 1, 1.5, 2, 2.5, 3, 3.5, and 4 mg. of citral, may be prepared and the trial 
comparison made against these, the final comparison being made with standards 
lying between 1.5 and 2.5 mg. with 0.25 mg. increments. 

It is absolutely essential to keep the reagents and comparison tubes at the re- 
quired temperature, 14°-16°C. Where the comparisons are made in a bath (this being 
possible only where the bath is of glass), the standards should be discarded within 
25 minutes after adding the sulphite-fuchsin solution. Give samples and standards 
identical treatment. 

CITRAL. 

Hiltner Method^. — Tentative. 

24 REAGENTS. 

(a) Meta-phenylendiamin hydrochlorid solution. — Prepare a 1% solution of meta- 
phenylendiamin hydrochlorid in 95% alcohol by volume. Decolorize, if neces- 
sary, by shaking with fuller's earth and filter through a double filter. The solution 
should be bright and clear, free from suspended matter, and practically colorless. 
Prepare this solution only for immediate use. 

(b) Alcohol. — For the analysis of lemon extracts, 90-95% alcohol by volume 
should be used, but for terpeneless extracts, 40-50% alcohol by volume is suflicient. 
Filter to remove any suspended matter. The alcohol need not be purified from 
aldehyde. If not practically colorless, render slightly alkaline with sodium hydroxid 
and distil. 

25 DETERMINATION. 

All of the operations may be carried on at room temperature. Weigh 25 grams 
of the extract into a 50 cc. graduated flask and make up to the mark with alcohol. 



264 METHODS OF ANALYSIS [Chap. 

Stopper the flask and mix the contents thoroughly. Pipette 2 cc. of this solution 
into a colorimeter tube; add 10 cc. of the meta-phenylendiamin hydrochlorid solu- 
tion and complete the volume to 50 cc. (or other standard volume) with alcohol. 
Compare at once the color with that of the standard, prepared at the same time, 
using 2 cc. of standard citral solution and 10 cc. of the meta-phenylendiamin hy- 
drochlorid solution, and making up to standard volume with alcohol. From the 
result of this first determination, calculate the amount of standard citral solution 
that should be used in order to give approximately the same citral strength as the 
sample under examination; then repeat the determination. 

26 TOTAL SOLIDS.-OFFICIAL. 

Proceed as directed under XVII, 5, employing 10 cc. of the sample measured 
at 20°C. 

27 ASH.-OFFICIAL. 

Ignite the residue froni 10 cc. of the extract as directed under VIII, 4. 

28 SUCROSE.— TENTATIVE. 

Neutralize the normal weight of the extract, evaporate to dryness, wash several 
times with ether, dissolve in water and determine as directed under VIII, 14 or 18. 

29 METHYL ALCOHOL.— TENTATIVE. 

Proceed as directed under XVII, 16, 17 or 18, using the distillate from the 
determination of alcohol, 18. 

Coloring Matters. 

30 GENER-aLL. tentative. 
Proceed as directed imder XI. 

31 LEMON AND ORANGE PEEL COLOR. 

Albrech Ulethod. — Tentatire. 
Place a few cc. of the extract in each of 2 test tubes; to one, add slowly 3-4 vol- 
umes of concentrated hydrochloric acid; to the other, several drops of concentrated 
ammonium hydroxid. If the color is due to lemon or orange peel only it is materi- 
ally deepened by such treatment. 

LEMON AND ORANGE OILS. 

32 specific gravity, -tentative. 
Determine the si>ecitic gravity at ~^o by means of a pycnometer. 

33 index of refraction.-tentative. 

Determine the index of refraction with any standard instrument, making the 
reading at 20°C. 

34 OPTICAL rotation.-tentative. 

Determine the rotation at 20°C. with any standard instrument, using a 50 mm. 
tube and sodium light. The results should be stated in angular degrees on a 100 
mm. basis. If instruments having the sugar scale are used, the reading on orange 
oils is above the range of the scale, but readings may be obtained by the use of 



XX] FLAVORING EXTUACTS 265 

standard laovo-rotatory quartz plativs, or by tlu; uao of a 25 mm. tubo. The true 
rotation cannot be obtained by diluting the oil with alcohol and correcting the 
rotation in proportion to the dilution. 

CITRAL. 

Kleber Method^. — Tentative. 

35 REAGENTS. 

(a) Phenylhydrazin solution. — Prepare a 10% solution in absolute alcohol. A 
sufficiently pure product can be obtained by distilling the commercial article, 
rejecting the first portions coming over which contain ammonia. 

(b) N/2 hydrochloric acid. 



36 



DKTEIIMINATION. 



Weigh 15 grams of the sample into a small, glass-stoppered flask; add 10 cc. of the 
phenylhydrazin solution. Allow to stand 30 minutes at room temperature, titrate 
with N/2 hydrochloric acid, using either methyl or ethyl orange as an indicator. 
Titrate similarly 10 cc. of the phenylhydrazin solution. The difference in the num- 
ber of cc. of N/2 acid used in these 2 titrations, multiplied by the fa(!tor 0.070, gives 
the weight of citral in the sample. If difficulty is experienced in detecting the end 
point of the reaction, titrate until the solution is distinctly acid, transfer to a sepa- 
ratory funnel, and draw off the alcoholic portion. Wash the oil with water, adding 
the washings to the alcoholic solution, titrate back with N/2 alkali and make the 
necessary corrections. 

37 Ilillner Method^. — Tentative. 

Weigh 2 grams of lemon oil or 8 grams of orange oil into a 100 cc. graduated flask, 
dilute to the mark with 95% alcohol by volume and proceed as under 25, using 
2 cc. of the dilute solution for the comparison. 

TOTAL ALDEHYDES. 

38 Chace Method. — Tentative. 

Weigh a small quantity of the sample into a small, stoppered flask and dilute 
with aldehyde-free alcohol in the proportion of 2 grams of lemon oil or 4 grams of 
orange oil to 100 cc. of solution. Determine th(! total aldehydes as directed under 
23, expressing the result as citral. 

39 PHYSICAL CONSTANTS OF THE 10 PER CENT DISTILLATE^ TENTATIVE. 

Place 50 cc. of the sample in a 3-bulb Ladenburg flask having the main bulb 6 
cm. in diameter and of 120 cc. capacity and the condensing bulbs of the following 
dimensions: 3.5 cm., 3 cm., 2.5 cm.; the distance from the bottom of the flask to 
the opening of the side arm should be 20 cm. Distil the oil at the rate of 2 cc. per 
minute until 5 cc. have been distilled. Determine the refractive index and rotation 
of this distillate as directed in 33 and 34. 

40 PINENE. 

Chace Method^. — Tentative. 

Mix the 10% distillate, obtained in 39, with 5 cc. of glacial acetic acid; cool the 
mixture thoroughly in a freezing bath and add 10 cc. of ethyl nitrite. Then add 



266 METHODS OF ANALYSIS [Chap. 

slowl}^ with constant stirring, 2 cc. of hydrochloric acid (2 to 1). Keep the mixture 
in the freezing bath 15 minutes. Filter off the crystals formed, using suction, and 
wash with 95% alcohol by volume. Return the combined filtrate and washings 
to the freezing bath for 15 minutes. Filter off the crystals formed, using the origi- 
nal filter paper. Wash the combined crops of crystals thoroughly with alcohol. 
Dry at room temperature and dissolve in a minimum amount of chloroform. Add 
methyl alcohol to the chloroform solution, a little at a time, until the nitroso- 
chlorids crystallize out, mount the separated and dried crystals in olive oil and 
examine under the microscope. Pinene nitroso-chlorid crystals have irregular 
pyramidal ends while limonene nitroso-chlorid crystallizes in needles. 

ALMOND EXTRACT. 

41 ALCOHOL.— TENTATIVE. 

Inasmuch as almond extract usually contains only about 1% of almond oil 
the alcohol can, in most cases, be calculated from the specific gravity of the 
extract. If the extract is high in solids, determine the alcohol as follows: Add 25 
cc. of the extract, measured at 20°C., to 75 cc. of saturated sodium chlorid solution 
in a separatory funnel and extract twice with 50 cc. portions of petroleum ether 
(b. p. 40°-60°C.). Collect the petroleum ether extract in a second separatory fun- 
nel and wash twice with 2 portions (25 cc.) of saturated brine. Combine the origi- 
nal salt solution with the washings; add a little powdered pumice and distil into a 
100 cc. flask. When almost 100 cc. have been distilled, make up to the mark with 
water at 20°C. and determine alcohol from the specific gravity, as directed under 

XVII, 4. 

BENZALDEHYDE.— TENTATIVE. 

42 REAGENT. 

Phenylhydrazin solution. — Add 1.5 cc. of glacial acetic acid to 20 cc. of water and 
mix with 1 cc. of phenylhydrazin. 



43 



DETERMINATION. 



Measure out 2 portions of 10 cc. each of the extract into 300 cc. Erlenmeyer 
flasks and add 10 cc. of the phenylhydrazin solution to 1 flask and 15 cc. to the 
other. Allow to stand overnight in a dark place, add 200 cc. of water and filter on 
a tared Gooch crucible, provided with a thin layer of asbestos. Wash first with cold 
water, finally with 10 cc. of 10% alcohol, and dry for 3 hours in a vacuum oven at 
70°C., or to constant weight over sulphuric acid. The weight of the precipitate 
multiplied by the factor 5.408 gives the weight of benzaldehyde in 100 cc. of the 
sample. If duplicate determinations do not agree, repeat the operation using a 
larger quantity of the phenylhydrazin solution. 

HYDROCYANIC ACID. 

44 Qualitative Test. — Tentative. 

Add several drops of ferrous sulphate solution and a single drop of ferric chlorid 
solution to several cc. of the extract. Mix thoroughly, add sodium hydroxid solu- 
tion, drop by drop, until no further precipitate forms and then dilute hydro- 
chloric acid to dissolve the precipitated hydroxids. In the presence even of small 
amounts of hydrocyanic acid, a Prussian blue coloration or suspension will develop. 



XX] 



FLAVORING EXTRACTS 



267 



45 Quantitative Method. — Tentative. 

(In the absence of chlorids.) 
Measure 25 cc. of the extract into a small flask and add 5 cc. of freshly precipi- 
tated magnesixim hydroxid (chlorin-free). Titrate with N/10 silver nitrate solu- 
tion, using potassium chromate as an indicator; 1 cc. of N/10 silver nitrate is 
equivalent to 0.00268 gram of hydrocyanic acid. 



46 



NITROBENZOL. 

Qualitative Test. — Tentative. 



Bail a few cc. of the extract with some zinc dust and acetic acid and filter. Add 
to the filtrate a drop of chloroform, make strongly alkaline with sodium hydroxid 
solution and heat. The presence of nitrobenzol in the original extract is indicated 
by the development of the characteristic odor of phenylisonitrile. 

CASSIA, CINNAMON AND CLOVE EXTRACTS. 
47 ALCOHOL.-TENTATIVE. 

Determine as directed under 41 . 



48 



OIL. 

Hortvet and West Method^. — Tentative. 



Transfer 10 cc. of the extract to a separatory funnel, add 30 cc. of water, acidify 
with 1 cc. of hydrochloric acid (1 to 1) and extract 3 times with ether, using not 
less than 100 cc. altogether. Wash the combined ether solutions twice with water 
and, in the case of cinnamon extract, dry by shaking with a small amount of granu- 
lated calcium chlorid. Transfer to a tared, wide-mouthed weighing bottle and evap- 
orate the ether as rapidly as possible on a boiling water bath, rotating the liquid 
upon the sides of the bottle in order to rid the residual oil of traces of ether. Weigh 
the residue and divide the weight by the specific gravity of the oil in order to ob- 
tain the per cent of oil by volimie. In the case of clove oil, allow the weighing bottle 
to remain in the balance case until the usual film of moisture has evaporated. The 
time of weighing, however, should not be delayed over 3 minutes. 

Determine the refractive index of the residual oils at 20°C. 

Dissolve a drop of the oil in several drops of alcohol and add a drop of ferric 
chlorid solution. The following tabulation gives the specific gravity, refractive 
index at 20°C. and color reaction with ferric chlorid solution: 



OIL 


SPECIFIC GRAVITY 


REFRACTIVE INDEX 
AT 20°C. 


COLOR REACTION 

WITH FERRIC 

CHLORID SOLUTION 


Cassia . 


1.05 
1.03 
1.055 


1.5S5-1.600 
1.590-1.599 
1.560-1.565 


Brown 


Cinnamon 


Green 


Cloves 


Deep blue 







GINGER EXTRACT. 

49 ALCOHOL— TENTATIVE. 
Determine as directed under XVII, 4. 

50 SOLIDS.— TENTATIVE. 

Evaporate 10 cc. of the extract nearly to dryness on a water bath, dry for 2 hours 
in a water oven and weigh. 



268 METHODS OF ANALYSIS [Chap. 

GINGER, 

51 Seeker Method. — Tentative. 

Dilute 10 cc. of the extract to 30 cc, evaporate to 20 cc, decant into a separa- 
tory funnel and extract with an equal volume of ether. Allow the ether to evaporate 
spontaneously in a porcelain dish, and to the residue add 5 cc. of 75% sulphuric acid 
and about 5 mg. of vanillin. Allow to stand 15 minutes and add an equal volume 
of water; in the presence of ginger extract an azure blue color develops. 

CAPSICUM. 

52 La Wall Method Modified by Doyle. — Tentative. 

To 10 cc. of the extract add cautiously dilute sodium hydroxid solution until the 
solution reacts very slightly alkaline with litmus paper. Evaporate at about 70°C. 
to approximately one fourth the original volume, render slightly acid with dilute 
sulphuric acid, testing with litmus paper. Transfer to a separatory funnel, rinsing 
the dish with water, and extract with an equal volume of ether, avoiding emulsi- 
fication by shaking the funnel gently 1-2 minutes. Draw off the lower layer and 
wash the ether extract once with about 10 cc. of water. Transfer the washed ether 
extract to a small evaporating dish, render decidedly alkaline with N/2 alcoholic 
potassium hj'droxid and evaporate at about 70°C. until the residue is pasty; then 
add about 20 cc. more of N/2 alcoholic potash and allow to stand on a steam bath 
until the gingerol is completely saponified (about 30 minutes). Dissolve the residue 
in a little water and transfer with water to a small separatory funnel. The volume 
should not exceed 50 cc. Extract the alkaline solution with an equal volume of 
ether. Wash the ether extract repeatedly with small amounts of water until no 
longer alkaline to litmus. Transfer the washed extract to a small evaporating dish, 
and allow the ether to evaporate spontaneously. Finally test the residue for capsi- 
cum by moistening the tip of the finger, rubbing it on the bottom and sides of the 
dish, and then applying the finger to the end of the tongue. A hot, stinging or 
prickly sensation, which persists for several minutes, indicates capsicum or other 
foreign pungent substances. 

PEPPERMINT, SPEARMINT AND WINTERGREEW EXTRACTS. 

53 ALCOHOL.— TENTATIVE. 
Proceed as directed under 41 . 

OIL. 

54 Howard Method^^ Modified. — Tentative. 

Pipette 10 cc. of the extract into a Babcock milk bottle, add 1 cc. of carbon di- 
sulphid, mix thoroughly, then add 25 cc. of cold water and 1 cc. of concentrated 
hydrochloric acid. Close the mouth of the bottle and shake vigorously; centrif- 
ugalize for 6 minutes and remove all but 3-4 cc. of the supernatant liquid, which 
should be practically clear, by aspirating through a glass tube of small bore. 
Connect the stem of the bottle with a filter pump, immerse the bottle in water kept 
at approximately 70°C. for 3 minutes, remove from the bath every 15 seconds and 
shake vigorously. Continue in the same manner for 45 seconds, using a boiling water 
bath. Remove from the bath and shake while cooling. Disconnect from the suc- 
tion and fill the bottle to the neck with saturated salt solution at room temperature, 
centrifugalize for 2 minutes and read the volume of the separated oil from the top 
of the meniscus. Multiply the reading by 2 to obtain the per cent of oil by volume. 



XX] FLAVORING EXTRACTS 269 

In the case of wintergreen, use as a floating medium a mixture of 1 volume of con- 
centrated sulphuric acid and 3 of saturated sodium sulphate solution. 

METHYL SALICYLATE IN WINTERGREEN EXTRACT. 

55 Hortvet and West Method^ Modified. — Tentative. 

Mix 10 cc. of the extract with 10 cc. of 10% potassium hydroxid solution. Heat 
on the steam bath until the volume is reduced about one half, add a distinct excess 
of hydrochloric acid (1 to 1), cool and extract with 3 portions of ether, 40, 30 and 
20 cc, respectively. Filter the extract through a dry filter into a weighed dish, wash 
the paper with 10 cc. of ether and allow the filtrate and washings to evaporate spon- 
taneously. Dry in a desiccator containing sulphuric acid and weigh. Multiply 
the weight of salicylic acid so found by 9.33 to obtain the per cent by volume of 
wintergreen oil in the sample. 

ANISE AND NUTMEG EXTRACTS. 
OIL. 

56 Hortvet and West Method^. — Tentative. 

To 10 cc. of the extract in a Babcock milk bottle add 1 cc. of hydrochloric acid 
(1 to 1), then sufiicient half saturated salt solution, previously heated to 60°C., to 
fill the flask nearly to the neck. Cork and let stand in water at 60°C. for about 15 
minutes, rotate occasionally and centrifugalize for 10 minutes at about 800 revo- 
lutions per minute. Add brine till the oil rises into the neck of the bottle, and again 
centrifugalize for 10 minutes. If the separation is not satisfactory, or the liquid is 
not clear, cool to about 10°C. and centrifugalize for an additional 10 minutes. 
Multiply the reading by 2 to obtain the percentage of oil by volume. 

BIBLIOGRAPHY. 

1 J. Am. Chem. Soc, 1899, 21: 256; 1902, 24: 1128; 1905, 27: 719. 

2 U. S. Bur. Chem. Bull, 132, p. 109. 

3 Ibid., 152, p. 148. 

* J. Am. Chem. Soc, 1906, 28: 1472. 

« U. S. Bur. Chem. Bull. 132, p. 102. 

« Ibid., 137, p. 72. 

^ Schimmel and Co. Semi-annual Report. Oct. 1898, p. 41. 

8 U. S. Bur. Chem. Circ 46, p. 9. 

9 J. Ind. Eng. Chem., 1909, 1: 84. 
i»Ibid., 1911, 3:252. 



XXI. MEAT AND MEAT PRODUCTS. 

MEAT. 

1 PREPARATION OF SAMPLE.— TENTATIVE. 

In the case of fresh meat, separate the sample as completely as possible from the 
bones and pass through a sausage mill rapidly and repeatedly until thoroughly 
mixed and macerated. Chill the sample to prevent decomposition and begin all 
determinations as soon as practicable after the sample is prepared. 

In the case of canned meats, pass the entire contents of a can through a sausage 
mill as directed above. Remove sausage from the casings and mix by repeated 
grinding in a sausage mill. Dry the portion of the sample, which is not needed 
for analysis, either in vacuo or by evaporating with alcohol, extract the fat with 
gasoline (b. p. below 60°C.), allow the gasoline to evaporate spontaneously and 
expel the last traces by heating for a short time on the steam bath. Do not 
heat the meat or separated fat longer than necessary, owing to the tendency of the 
latter to decompose. Reserve the fat for examination according to the methods 
given under XXIII. Keep the fat in a cool place and complete the examination 
before the fat becomes rancid. 

2 MOISTURE.— TENTATIVE. 

Proceed as directed under VIII, 2 or 3, using the latter method in cases in which 
it is desired to employ the dried sample for further determinations. 

3 ASH.— OFFICIAL. 
Proceed as directed under VIII, 4. 

4 CRUDE FAT OR ETHER EXTRACT.— OFFICIAL. 

Proceed as directed under VIII, 10. 

5 TOTAL PHOSPHORUS.— TENTATIVE. 

Destroy the organic matter as directed under 1, 5 (a), (b), (C) or (d) and proceed 
as directed under I, 6 or 9. 

WATER-SOLUBLE PHOSPHORUS'.— TENTATIVE. 

6 PREPARATION OP SOLUTIONS. 

(a) Cold water extract of flesh. — Weigh out 10-12 grams of fresh muscle and di- 
vide equally between 2 small beakers. Moisten the sample with a few cc. of water, 
and break up the lumps with a glass rod. Add 50 cc. of water to each beaker and 
stir the contents for 15 minutes. Allow the insoluble residue to settle for 3-5 min- 
utes, decant the Uquid through filters into beakers and add 25 cc. of water to each 
residue. Stir 7-8 minutes and, after allowing to settle, decant onto the same filter. 
Continue this treatment, using 25 cc. of water each time, until the filtrates measure 
about 230 cc. each. Allow the filters to drain completely between extractions. 
Whenever the major portion of the residue has been mechanically transferred to the 
filter, return it to the beaker. After the last extraction, transfer the entire con- 

271 



272 METHODS OF ANALYSIS [Chap. 

tents of each beaker onto the filter and, when drained, wash twice with small quan- 
tities of water. Combine the 2 extracts. 

(b) Hoi water -ammonium sidphale extract of blood. — Weigh out 30-35 grams of 
fresh whole blood as caught from the animal into a porcelain mortar. Grind and 
transfer to a 400 cc. beaker with hot water. Make up to about 150 cc. with boil- 
ing water. Place over a flame, gradually bring to boiling, with constant stirring, 
then add 20 cc. of 20% ammonium sulphate solution and continue boiling, with 
constant stirring, for about 10 minutes. Decant onto an 18 cm. filter paper, re- 
ceiving the filtrate in an 800 cc. beaker. Transfer the coagulum from the filter, 
along with that remaining in the beaker, to a mortar. Grind to a smooth paste 
and transfer to a beaker with boiling 85% ammonium sulphate solution. Make up 
to about 50 cc. with the latter, stir for 8 minutes and again filter. Return the 
coagulum to the mortar and grind again, transferring to the beaker as before with 
boiling 83% ammonium sulphate solution. Repeat this process of 8 minute extrac- 
tions of the coagulum in 85% ammonium sulphate solution and filtration as directed 
above, without further grinding, until the filtrate measures a})out 450 cc. Wash out 
each beaker twice with 8-10 cc. of hot 3|% ammonium sulphate solution, transferring 
the coagulum and extract to the filter. Wash the coagulum twice with boiling 3 j% 
ammonium sulpliate solution from a wash bottle. Always allow the filter to drain 
well between additions of extract or wash solutions. 

(C) Hot loater -ammonium sulphate extract of liver. — Weigh by difference from a 
closed weighing bottle 15-20 grams of finely ground liver into a 400 cc. beaker. Add 
a few cc. of cold water and beat up with a stirring rod to separate the particles of 
tissue. Add enough boiling water to make the volume about 150 cc, place over a 
flame and bring to boiling. Add 10 cc. of 20% ammonium sulphate solution and 
continue to boil for 10 minutes. Allow to settle for a moment and decant the boil- 
ing hot liquid onto an 18 cm. filter. Add 50 cc. of boiling water and stir for 8 min- 
utes, without further heating, and decant onto the filter again. Repeat this addi- 
tion of 50 cc. of hot water, stirring and decanting 8 times, returning the coagulum 
to the beaker as soon as any considerable amount collects upon the filter. With 
the eighth portion of water transfer the entire contents of the beaker onto the filter 
and wash twice with hot water. Always allow the filter to drain well between 
additions of extract or wash water. 

(d) Hot water-am.mo7iium sidphale extract of brain. — Weigh out about 10 grams 
of brain into a 250 cc. beaker. Add a few cc. of water and work up the brain and 
water with a glass rod. Make up to about 100 cc. with boiling water, place over a 
flame, and gradually bring to boiling, with constant stirring. While boiling vigor- 
ously (not before) add 20 cc. of 20% ammonium sulphate solution, boil gently for 
about 10 minutes, allow to settle for a moment and decant slowly onto a linen filter 
containing acid-washed, glassmakcr's sand, receiving the extract in an 800 cc. 
beaker. Add to the beaker containing the coagulum 50 cc. of 33% ammonium 
sulphate solution, stir 1 minute, keep boiling and decant the liquid onto the filter. 
Repeat this process of 1 minute extractions of the coagulum in 83% ammonium 
sulphate solution, and filtration as directed above, until the filtrate measures al)out 
450 cc. Wash out the beaker twice with 8-10 cc. of hot 8}% ammonium sulpliate 
solution, completing the transfer of the coagulum and extract to the sand, and wash 
the coagulum twice with the wash solution. Always allow the filter to drain well 
between additions of extract or wash solution. 

In making extracts of brain, give careful attention to the handling of the sample. 
The coagulum is very soft. It slioukl be stirred only enough to keep it in motion. 
If handled roughly in returning from the sand filter to the beaker, it becomes too 



XXI] MEAT AND MEAT PRODUCTS 273 

finely divided and retains a f^reat, deal of liquid. To prevent the extract or the 
coaRulum from eoniinfi; into contact with the lincMi before [jassin^ throuf2;h tiie sand, 
pour the extract .slowly into a slif^ht depression in the (tenter of the sand or, better 
yet, into a thi,n film of absorbent cotton, 1| inches in diameter, laid over a deijres- 
sion in the sand. The coaRulum remai,ns on the cotton and its return to tlie l)eaker 
is facilitated thereby. If tlie cotton is not brokcui up by needless stii'rin^, it <'an be 
taken out of the beaker with a shiss rod and returned to the sand ea<;li time a i)artiai 
extract is to be filtered. Care is necessary to prevent loss throu^^h bumpin<i, on 
account of sand in the beakers duriiifz; the final extractions. l']ach partial extract 
should be boilinj; hot at the time filtration bejijins. 

7 DKTEUMINATION. 

To the extracts, prepared as directed in 6, add 50 cc. of magnesia mixture [I, 4 (C)] 
and stir thoroughly. Allow to stand 15 minutes, add 25 cc. of ammonium hy- 
droxid (sp. gr. 0.90), cover and allow to stand 3 days. Filter and wash the pre- 
cipitate with 2\% ammonium hydroxid. Dissolve the precipitate on the filter paper 
and that remaining in the beaker in nitric acid (1 to 1) and hot water, receiving 
the solution in a 400 cc. beaker. Neutralize witli ammonium hydroxid, make slightly 
acid with nitric acid, :idd 5 grams of ammonium nitrate and determine phosphorus 
as directed under I, 6. 

8 TOTAL NITROGEN.— OFFICIAL. 

Proceed as directed under I, 18, 21 or 23, using about 2 grams of the fresh 
sample. In the Kjeldalil and Gunning methods digest with sulphuric acid for at 
least 4 hours; in the Kjeldahl-Gunning-Arnold method for 2 hours after tlie mix- 
ture has become clear. 

9 SOLUBLE AND INSOLUBLE NITROGEN.— TENTATIVE. 

Exhaust 7-25 grams of the samj)le depending upon the water content in the fol- 
lowing manner: Weigh into a 150 cc. beaker, add 5-10 cc. of cold (15°C.) ammonia- 
free water and stir to a homogeneous paste. Then add 50 cc. of cold water, stir 
every 3 minutes for 15 minutes, let stand for 2-3 minutes and decant the liquid upon 
a quantitative filter, collecting the filtrate in a 500 cc. graduated flask. Drain the 
beaker, pressing out the liquid from the meat residue by the aid of a glass rod. 
Add to the residue in the beaker 50 cc. of cold water, stir for 5 minutes and, after 
standing 2-3 minutes, decant as before. If a considerable portion of the meat 
is carried over onto the filter, transfer it back to the beaker by means of a glass 
rod. Repeat the extractions, using the following additional amounts of cold water: 
50, 50, 25, 25, 25 and 25 cc. After the last extraction transfer the entire insoluble 
portion to the filter and wash with three 10 cc. portions of water, allowing the ma- 
terial to drain thoroughly after each addition of water. Dilute to the mark, mix 
thoroughly and determine the total soluble nitrogen in a 50 cc. aliquot as directed 
under I, 18, 21 or 23. Subtract the percentage of soluble nitrogen from the per- 
centage of total nitrogen, 8, to obtain the percentage of insoluble nitrogen. To 
obtain the percentage of insoluble protein multiply the percentage of in3ohd>le 
nitrogen by 6.25. 

"10 CONNECTIVE TISSUE NITROGEN.— TENTATIVE. 

Exhaust 10 grams of the sample with cold water as directed under 9, and boil the 
exhausted residue repeatedly with successive portions of about 100 cc. of water 
until the total hot water extract amounts to approximately 1 liter. Filter, concen- 
trate and determine nitrogen in the concentrated extract. Multiply the percentage 
of nitrogen so obtained by 5.55 to obtain the percentage of nitrogenous substances 
of the connective tissue. 



274 METHODS OF ANALYSIS [Chap. 

11 COAGULABLE PROTEINS.— TENTATIVE. 

(For uncooked meat only.) 
Measure 150 cc. of the extract, from 9, into a 250 cc. beaker and evaporate to 40 
cc. on a steam bath, with occasional stirring. Neutralize to phenolphthalein, then 
add 1 cc. of N/1 acetic acid and boil gently for 5 minutes. The coagulum should 
separate out at once, leaving a clear liquid. Filter on quantitative paper, wash 
the beaker thoroughly 4 times with hot water, taking special care to clean the sides. 
Finally wash the coagulum on the filter 3 times, dilute the combined filtrate and 
washings to a definite volume and reserve for the determination of proteoses, pep- 
tones and gelatin, 12, and creatin, 16. Transfer the coagulum with the paper to a 
Kjeldahl flask and remove, with concentrated sulphuric acid, any of the material 
adhering to the beaker, taking the usual 25 cc. of acid in 5 cc. portions for this pur- 
pose, heating the acid in the beaker on a hot plate and rubbing with a glass rod. 
Proceed as directed under 8. Multiply the percentage of nitrogen obtained by 6.25 
to obtain the percentage of coagulable proteins. 

PROTEOSES, PEPTONES AND GELATlli. 

12 Modified Tannin-Salt Method^. — Tentative. 

Transfer a 50 cc. aliquot of the filtrate, obtained in 11, to a 100 cc. graduated 
flask, add 15 grams of sodium chlorid and 10 cc. of cold water, shake until the so- 
dium chlorid has dissolved and cool to 12°C. Add 30 cc. of 24% tannin solution, 
cooled to 12°C., fill to the mark with water previously cooled to 12°C., shake and 
allow the mixture to stand at a temperature of 12°C. for 12 hours or overnight. 
Filter at 12°C., transfer 50 cc. of the filtrate to a Kjeldahl flask and add a few drops 
of sulphuric acid. Place the flask in a steam bath, connect with a vacuum pump 
and evaporate to dryness. Determine nitrogen in the residue as directed in I, 18, 
using 30 cc. of sulphuric acid for the digestion. Conduct a blank determination, 
using the same amount of reagents, and correct the result accordingly. Mul- 
tiply the corrected result by 2 and deduct the amount of nitrogen as found from the 
nitrogen determined in another 50 cc. aliquot of the filtrate from the coagulable 
proteins without the tannin-salt treatment; the difference multiplied by 6.25 gives 
the percentage of proteoses, peptones and gelatin. 

13 MEAT BASES.— TENTATIVE. 

Deduct from the percentage of total nitrogen, 8, the sum of the percentages of 
nitrogen, obtained in the determination of insoluble proteins, 9, coagulable pro- 
teins, 11, and proteoses, peptones and gelatin, 12, to obtain the percentage of 
nitrogen of the meat bases. Multiply the result by 3.12 to obtain the percentage of 
meat bases. 

AMMONIA. 
Folin Aeration Method^. — Tentative. 

•4 APPARATUS. 

Employ the apparatus illustrated in Fig. 9 ; 4 is a wash bottle one fourth full of 
10% sulphuric acid; iS is a tube containing the sample; C is a rubber disc and D is a 
5 cc. bulb to prevent spray from being carried over into the tube {E) which contains 
the standard acid \ F is a, safety bottle. 

15 DETERMINATION. 

Introduce 2-4 grams of the finely divided meat into the tube {B) and add 20 cc. 
of ammonia-free water. Place a measured amount of N/25 or N/50 sulphuric or 



XXIl 



MEAT AND MEAT PRODUCTS 



275 



hydrochloric acid in tube (E). Then add 1 cc. of saturated potassium oxalate solu- 
tion to the sample in tube (B), introduce a few drops of kerosene and finally add 
just sufficient saturated potassium carbonate solution to render the mixture alkaline. 
Place the tubes in position at once, pass air through the apparatus and titrate the 
standard acid in tube (E) at hourly intervals, until ammonia ceases to be given off, 
using methyl red, cochineal or congo red as an indicator. If preferred, the ammonia, 
collected in tube (E), may also be determined by nesslerizing as directed under 

IV, 11. 



16 



CREATIN.— OFFICIAL. 



Evaporate an aliquot or the remaining portion of the filtrate and washings from 
the coagulable proteins, 1 1 , (a portion having been used in 12), to 5-10 cc, transfer 
with a minimum amount of hot water to a 50 cc. measuring flask, keeping the volume 
below 30 cc, add 10 cc. of 2N hydrochloric acid and mix. Hydrolyze in an auto- 



TO Suction 




FIG. 9. APPARATUS FOR THE FOLIN AMMONIA DETERMINATION. 



clave at 117°-120°C. for 20 minutes, allow the flask to cool somewhat, remove and 
chill under running water. Partially neutralize the excess of acid by adding 7.5 cc. 
of 10% sodium hydroxid solution, free from carbonates, dilute to the mark and 
mix. Make a preliminary reading on 20 cc. to ascertain the volume to use to obtain 
a reading of approximately 8 mm. and transfer to a 500 cc. graduated flask. Add 
10 cc. of 10% sodium hydroxid solution and 30 cc. of saturated picric acid solution 
(1.2%). Mix and rotate for 30 seconds and let stand exactly 4^ minutes. Dilute 
to the mark at once with water, shake thoroughly and read in a Duboscq colori- 
meter, comparing the color with N/2 potassium dichromate solution, set at 8 mm. 
If the reading is too high or too low (above 9.5 or below 7 mm.), calculate the 
quantity necessary to obtain a reading of about 8 mm. The strength of the dichro- 
mate solution used must be checked against a standard creatin solution. To obtain 
the values, divide 81 by the reading and multiply by the volume factor to obtain mg. 
of creatinin; this value multipUed by 1.16 gives creatin, which, divided by the weight 
of the sample and multiplied by 100 gives the per cent of creatin. 



276 METHODS OF ANALYSIS [Chap. 

The use of Kober's shade and the painting of the plunger, as suggested for this 
nephelometer, assists in getting a sharper end point, relieves the eye strain and 
may be employed if desired. 

Example. — 20 grams of meat are extracted with water as in 9, and the extract 
diluted to 500 cc; 150 cc. of this latter solution (equivalent to 6 grams of meat) are 
treated as in 11. The filtrate thus obtained is then evaporated and hydrolyzed as 
above and then diluted to 50 cc. ; 25 cc. of this last solution are treated with sodium 
hydi'oxid solution and picric acid solution as directed above and diluted to 500 cc. 
This latter solution gives a reading of 9 mm. 

81 , , 50 
9 



50 
X ^ = 18 mg. creatinin; 

Q"^^XV^X^QQ =:0.35%creatin. 



6 

STARCH. 
(In chopped meat, sausage, deviled meat, etc.) 

17 Qualitative Test. — Tentative. 

Treat 5-6 grams of the sample with boiling water for 2-3 minutes, cool the mix- 
ture and test the supernatant liquid with iodin solution. In using this test, a small 
amount of starch may be present as the result of the use of spices. If a marked 
reaction is given, however, it may be concluded that starch or flour has been added, 
and a quantitative determination may be made. The qualitative method may be 
replaced by a microscopic examination, which discloses not only the presence of 
added starch, but also the variety employed. 

18 Mayrhofer Method, Price Modification*. — Tentative. 

Treat in a 200 cc. beaker 10 grams of the finely divided sample with 75 cc. of an 
8% solution of potassium hydroxid in 95% alcohol by volume and heat on a steam 
bath until all the meat is dissolved (30-45 minutes). Add an equal volume of 95% 
alcohol, cool and allow to stand for at least an hour. Filter by suction through a 
thin layer of asbestos in a Gooch crucible. Wash twice with warm 4% potassium 
hydroxid in 50% alcohol by volume and then twice with warm 50% alcohol. Dis- 
card the washings. Retain as much of the precipitate in the beaker as possible 
until the last washing. Place the crucible with contents in the original beaker, 
add 40 cc. of water and 25 cc. of concentrated sulphuric acid. Stir during the addi- 
tion of the acid and make sure that the acid comes in contact with all the precipi- 
tate. Allow to stand about 5 minutes, add 40 cc. of water and heat just to boiling, 
stirring constantly. Transfer the solution to a 250 cc. graduated flask, add 2 cc. 
of 20% phosphotungstic acid solution, allow to cool to room temperature and make 
up to the mark with water. Filter through a starch-free filter paper, pipette 100 
cc. of the filtrate into a 200 cc. graduated flask, neutralize with sodium hydroxid 
solution, make up to volume and determine the dextrose present in a 50 cc. portion 
of the filtrate, as directed under VIII, 25, titrating the cuprous oxid precipitate 
as directed under VIII, 29. The weight of the dextrose multiplied by 0.9 gives 
the weight of the starch. 

GLYCOGEN. 

19 Qualitative Test^. — Tentative. 

Boil 50 grams of the macerated sample with 50 cc. of water for 15-30 minutes. 
Filter the broth through moistened filter paper or fine linen. To a portion of the 
filtrate in a test tube add a few drops of a mixture of 2 parts of iodin, 4 of potassium 



XXI] MEAT AND MEAT PRODUCTS 277 

iodid and 100 of water. In the presence of a considerable amount of glycogen the 
latter produces a dark brown color, which is destroyed by heating and reappears 
on cooling. When starch is present, it may be precipitated by treating the water 
extract with 2 volumes of glacial acetic acid, filtering and applying the test for 
glycogen to the filtrate. 

Trowbridge and Francis Method^. — Tentative. 

20 PREPABATION OF SOLUTION. 

Weigh out by difference about 25 grams of the finely ground and thoroughly 
mixed sample. Place in a 400 cc. beaker and mix with 50 cc. of potassium hydroxid 
solution (1| to 1), free from carbonate. Cover the beaker with a watch glass and 
digest on the water bath for 2 hours, with occasional stirring. At the end of the 2 
hours, dilute to approximately 200 cc. with cold water. 

Add to the solution an equal volume of 95% alcohol by volume, cover with a 
watch glass and set aside for 10-12 hours. Decant the supernatant liquid through a 
folded 18.5 cm. filter, allowing the glycogen to remain in the beaker and wash by 
decantation with 66% alcohol (2 volumes of 95% alcohol to 1 of water) until the 
glycogen is white, or nearly so. Usually about 4 washings are required. Transfer 
the washed precipitate from the beaker to the filter and wash 2-3 times with 66% 
alcohol. The solution filters slowly and the funnel should be covered with a watch 
glass to prevent excessive evaporation. The albuminous substance present retards 
the filtration if permitted to dry on the paper. If the washing by decantation is not 
made nearly complete, it will be difficult to obtain the glycogen free from the coloring 
matter. 

After the washing is completed, close the bottom of the funnel by a piece of rub- 
ber tubing and a pinch-cock. Fill the funnel with warm water, cover with the watch 
glass and let stand 2-3 hours, or overnight. Open the pinch-cock and allow all 
of the solution to pass through the filter into a beaker. Close the funnel with the 
pinch-cock and fill with warm water as before. Allow this water to remain in the 
funnel for an hour and then filter as before. At first the glycogen solution appears 
quite turbid. This washing with warm water should be continued until the filtrate 
becomes perfectly clear. To the solution of glycogen in water, add double its 
volume of 95% alcohol by volume and let stand overnight to complete the repre- 
cipitation of the glycogen. Filter and wash as before with 66% alcohol. 

21 DETERMINATION. 

If desired, the last filtration may be made through a tared Gooch crucible and the 
weight of glycogen determined after drying to constant weight. This gives results 
that are approximately correct. More satisfactory results are obtained by hydrolyz- 
ing the glycogen with dilute hydrochloric acid and determining the resultant dex- 
trose. Dissolve the glycogen on the filter in warm water as directed above, collect- 
ing the filtrate and washings in a 300 cc. graduated flask and keeping the volume 
within 225 cc. Add 12.5 cc. of hydrochloric acid (sp. gr. 1.19) to the combined fil- 
trate and washings, mix and place in a boiling water bath for 3 hours. Cool, neu- 
tralize with sodium hydroxid solution, cool again, make up to volume with water 
and determine dextrose in an aliquot of the solution as directed under VIII, 54, 
determining the reduced copper as directed under VIII, 29. Multiply the cor- 
responding weight of dextrose by 0.9 to obtain its equivalent of glycogen and correct 
this result for dilution to obtain the per cent of glycogen in the sample. 



278 METHODS OF ANALYSIS [Chap. 

SUGAR'.— TENTATIVE. 

22 REAGENTS. 

(a) Mercuric nitrate solution. — Warm 220 grams of yellow mercuric oxid with 
300 cc. of water and treat with small portions of nitric acid, stirring until dissolved. 
Make up to 1 liter and filter. 

(b) Phosphotungstic acid solution. — Prepare a 20% solution of phosphotungstic 
acid in 2.5% hydrochloric acid. 

23 DETERMINATION. 

Boil 100 grams of the sample with about 350 cc. of water for about 20 minutes, 
cool, add an excess (10-30 cc.) of the mercuric nitrate solution, nearly neutralize 
with sodium hydroxid solution and make up to 500 cc, exclusive of fat. Mix thor- 
oughly, allow the mixture to settle and decant the clear liquid through a large, dry, 
folded filter. To an aliquot of the filtrate add 1-2 cc. of concentrated hydrochloric 
acid for each 100 cc, heat to boiling and saturate thoroughly with a rapid current 
of hydrogen sulphid. Remove the excess of hydrogen sulphid by means of a cur- 
rent of air, cool, make up to a definite volume with water and filter. To an aliquot 
of the filtrate add an excess of the phosphotungstic acid solution, noting the in- 
crease in volume of the solution caused by this addition and place in an ice box 
for several hours or overnight. Filter, introduce 50 cc. of the filtrate into a 400 cc. 
beaker, neutralize with concentrated sodium hydroxid solution, add 50 cc. of Soxh- 
let's solution [VIII, 19], heat so that boiling begins in 4 minutes, boil 2 minutes and 
filter through an alundum crucible of suitable porosity, using very gentle suction. 
If the filtrate is green or yellow, refilter through the same crucible until the fil- 
trate is clear blue. Wash the precipitate with a very small amount of 5% sodium 
hydroxid solution, refiltering the washings if they are turbid. Dissolve the precipi- 
tated cuprous oxid in nitric acid (1 to 1) and determine copper as directed under 
VIII, 29. Find the corresponding amount of dextrose or invert sugar from VIII, 
27, and calculate the per cent in the original sample by proper correction for the 
various aliquots taken in the determination. To convert invert sugar to sucrose 
multiply by the factor 0.95. 

NITRATES. 
Schlosing-Wagner Method^. — Tentative. 

24 REAGENT. 

Ferrous chlorid solution. — Dissolve nails or other small pieces of iron in concen- 
trated hydrochloric acid, keeping an excess of iron present until the evolution of gas 
ceases. Keep the solution in 50 cc. glass-stoppered bottles entirely filled. Employ 
only freshly opened bottles of the reagent for the determination. 

25 APPARATUS. 

Provide a 250 cc flask with a 2-holed rubber stopper. Through one of the holes 
pass the stem of a funnel having a glass stop-cock, and into the other fit a delivery 
tube leading downward at an angle from the flask to a trough containing water. 
Terminate the upper end of the delivery tube just below the rubber stopper in 
the flask and place the lower end under the surface of the water in the trough, the 
exit being immediately beneath the mouth of an inverted measuring tube, filled 
with 40% potassium hydroxid solution. Cover the trough end of the delivery tube 
with a piece of rubber tubing. Midway on the delivery tube between the flask and 
the measuring tube place a short length of rubber tubing and a pinch-cock. 



XXI ] MEAT AND MEAT PRODUCTS 279 



26 



DETERMINATION. 



Extract 100 grams of finely ground meat by boiling repeatedly with successive 
small portions of water, decanting the extracts through a muslin or paper filter 
into a casserole, and concentrate the combined extracts to a volume of about 50 cc. 

Introduce 50 cc. of the ferrous chlorid solution and 50 cc. of 10% hydrochloric acid 
into the flask, close the stop-cock of the funnel, open the pinch-cock on the delivery 
tube, move the end of the latter so that escaping air will not pass into the measuring 
tube, and boil the contents of the flask until the air is expelled, as indicated by a 
slight pressure against the fingers when the rubber tubing is compressed after mo- 
mentary removal of the flame. Now close the delivery tube with the pinch-cock 
and place the exit end beneath the measuring tube. Introduce the concentrated 
extract of the sample into the flask, a little at a time, through the funnel tube, 
opening the pinch-cock on the delivery tube and boiling the contents of the flask 
at intervals to force the nitric oxid gas into the measuring tube. Finally rinse the 
casserole and the funnel tube with a little boiled water, add the rinsings to the con- 
tents of the evolution flask in the manner just described and boil until nitric oxid 
no longer passes over into the measuring tube. Calculate the volume of nitric 
oxid at 0°C. and 760 mm. pressure. One cc. of nitric oxid at 0°C. and 760 mm. 
pressure is equivalent to 0.004512 gram of potassium nitrate. 

Phenoldisulphonic Acid Method^. — Tentative. 

27 REAGENTS. 

(a) Phenoldisulphonic acid solution. — Heat 6 grams of phenol with 37 cc. of con- 
centrated sulphuric acid on a water bath, cool and add 3 cc. of water. 

(b) Standard comparison solution. — Dissolve 1 gram of pure, dry potassium ni- 
trate in water and dilute to 1 liter. Evaporate 10 cc. of this solution to dryness 
on a steam bath, add 2 cc. of the phenoldisulphonic acid solution, mix quickly and 
thoroughly by means of a glass rod, heat for about a minute in a steam bath and 
dilute to 100 cc. One cc. of this solution is equivalent to 0.1 mg. of potassium ni- 
trate. Prepare a series cf standard comparison tubes by introducing amounts 
ranging from 1-20 cc. of this solution (0.1-2.0 mg. of potassium nitrate) into 50 cc. 
Nessler tubes, adding 5 cc. of strong ammonium hydroxid to each and diluting to 
50 cc. These standard tubes are permanent for several weeks if kept tightly 
stoppered. 

28 DETERMINATION. 

Weigh 1 gram of the sample into a 100 cc. flask, add 20-30 cc. of water and heat 
on a steam bath for 15 minutes, shaking occasionally. Add 3 cc. of saturated silver 
sulphate sohition for each per cent of sodium chlorid present, then 10 cc. of basic 
lead acetate solution and 5 cc. of alumina cream, shaking after each addition. 
Make up to the mark with water, shake and filter through a folded filter, returning 
the filtrate to the filter until it runs through clear. Evaporate 25 cc. of the filtrate 
to dryness, add 1 cc. of the phenoldisulphonic acid solution, mix quickly and thor- 
oughly by means of a glass rod, add 1 cc. of water and 3 or 4 drops of concentrated 
sulphuric acid and heat on a steam bath for 2-3 minutes, being careful not to char 
the material. Then add about 25 cc. of water and an excess of ammonium hydroxid, 
transfer to a 100 cc. graduated flask, add 1-2 cc. of alumina cream if not perfectly 
clear, dilute to the mark with water and filter. Fill a 50 cc. Nessler tube to the 
mark with the filtrate and determine the amount of potassium nitrate present in 



280 METHODS OF ANALYSIS [Chap. 

the sample by comparison with the standard comparison tubes. If the solution is 
too dark for comparison with the standards, dilute with water and correct the 
result accordingly. 

29 PRESERVATIVES.— TENTATIVE. 

Proceed as directed under X. 

30 METALS.— TENTATIVE. 
Proceed as directed under XII. 

3-| COLORING MATTERS.— TENTATIVE. 

Proceed as directed under XI. 

MEAT EXTRACTS AND SIMILAR PRODUCTS. 

32 PREPARATION OF SAMPLE.— TENTATIVE. 

Remove liquid and semi-liquid meat extracts and similar preparations from the 
container and mix thoroughly before sampling. A little heating expedites the 
mixing of pasty extracts. In many liquid preparations a sediment forms which 
should be carefully removed from the bottom of the container and included in the 
sample. If the sample is in the form of cubes, grind 10-12 of the cubes in a mortar. 

33 MOISTURE.— TENTATIVE. 

Proceed ae directed under VIII, 2, employing about 2 grams of powdered prepa- 
rations, about 3 grams of pasty preparations, or 5-10 grams of liquid extracts, 
according to the solid content. Dry the powdered preparations directly without 
admixture. Dissolve the pastj^ preparations in water and dry with sufficient ignited 
sand, asbestos or pumice stone to absorb the solution. When glycerol is present, 
proceed as directed under VIII, 3. 

34 ASH.— OFFICIAL. 

Proceed as directed under VIII, 4. Add sufficient water to pasty preparations 
to effect solution and evaporate to dryness in order that the solids may be distrib- 
uted evenly over the bottom of the dish. 

35 TOTAL PHOSPHORUS.— TENTATIVE. 

Proceed as directed under 5. 
3g CHLORIN.— TENTATIVE. 

Dissolve about 1 gram of the sample, prepared as directed in 32, in 20 cc. of 5% 
sodium carbonate solution and proceed as directed under III, 18. 

37 FAT.— TENTATIVE. 

Transfer the residue from the determination of moisture to a continuous extrac- 
tion apparatus and proceed as directed under VIII, 10. 

38 TOTAL NITROGEN.— OFFICIAL. 

Proceed as directed under I, 18, 21 or 23. 



XXI] MEAT AND MEAT PRODUCTS 281 

39 INSOLUBLE PROTEINio.— TENTATIVE. 

Dissolve 5 grams of powdered preparations, 8-10 grams of pasty extracts, or 20- 
25 grams of fluid extracts, in cold water. Filter and wash with cold water. Trans- 
fer the filter paper and contents to a Kjeldahl flask and determine nitrogen as di- 
rected under 1, 1 8, 21 or 23. However, if a large amount of insoluble matter is pres- 
ent, transfer the weighed sample to a graduated flask, make up to a definite volume, 
shake thoroughly, filter through a folded filter and determine nitrogen in an aliquot 
of the filtrate. Deduct the percentage of nitrogen in the total filtrate from the. 
percentage of total nitrogen, 38, to obtain the percentage of nitrogen in the insol- 
uble protein. Multiply this percentage of nitrogen by 6.25 to obtain the percentage, 
of insoluble protein. 

40 COAGTJLABLE PROTEIN.— TENTATIVE. 

Prepare a solution of the sample as directed in 39. Employ as large an aliquot 
of the filtrate as practicable or an aliquot of the filtrate from the insoluble protein, 39, 
and neutralize to phenolphthalein by the addition of acetic acid or sodium hydroxid, 
whichever may be necessary, add 1 cc. of N/1 acetic acid, boil for 2-3 minutes, 
cool to room temperature, dilute to 500 cc. and pass through a folded filter. 

Determine nitrogen in 50 cc. of the filtrate as directed under I, 1 8, 21 or 23. 
Ten times the percentage of nitrogen so obtained subtracted from the percentage 
of soluble nitrogen (total nitrogen minus the percentage of nitrogen occurring as 
insoluble protein) gives the percentage of nitrogen present as coagulable protein. 
Multiply this figure by 6.25 to obtain the percentage of coagulable protein in the 
sample. 

41 AMMONLA.— TENTATIVE. 

Mix 1 gram of meat extract with 2 cc. of N/1 hydrochloric acid, wash into a FoHn 
apparatus with about 5 cc. of water and proceed as directed under 15. 

42 PROTEOSES AND GELATIN".— TENTATIVE. 

Evaporate the filtrate from 40 to a small volume and saturate with zinc sulphate 
(about 85 grams to 50 cc, avoiding such an excess as would later cause bumping). 
Let stand several hours, filter and wash the precipitate with saturated zinc sul- 
phate solution, place the filter and precipitate in a Kjeldahl flask and determine ni- 
trogen as directed under I, 1 8, 21 or 23. Or, if the precipitate is voluminous, which 
rarely happens, make up to a definite volume with saturated zinc sulphate solution, 
filter and determine the nitrogen in a,n aliquot of the filtrate, as directed under I, 
18, 21 or 23, and subtract the nitrogen thus obtained from the nitrogen in the 
filtrate from the coagulable protein to obtain the nitrogen of the precipitated 
protein (proteoses and gelatin). 

43 GELATIN.— TENTATIVE. 

Prepare a 50% solution of the sample, using hot water. Allow to cool and place 
in an ice box for 2 hours. If gelatin is present, the solution will set. 

The ratio of total creatinin to total nitrogen in a normal meat extract (1 : 1.5) 
assists in determining the presence of gelatin or gelatin derivatives. The ratio is 
decreased when gelatin or gelatin derivatives are present in any considerable 
amount. 



282 



METHODS OF ANALYSIS 



[Chap. 



AMINO NITROGEN. 

Van Slyke Method^^. — Tentative. 

44 REAGENTS. 

(a) Alkaline permanganate solution. — Dissolve 50 grams of potassium permanga- 
nate and 25 grams of potassium hydroxid in sufficient water to make 1 liter. 

(b) Sodium nitrite solution. — Dissolve 30 grams of sodium nitrite in sufficient 
water to make 100 cc. 

(C) Glacial acetic acid. 




FIG. 10. VAN SLYKE APPARATUS FOR THE DETERMINATION OF AMINO NITROGEN. 

{By courtesy of the Journal of Biological Chemisiry.) 

45 APPARATUS. 

Employ the apparatus shown in Figs. 10 and 11, the former illustrating the man- 
ner in which the entire apparatus is arranged and the latter showing the details 



XXI] 



MEAT AND MEAT PRODUCTS 



283 



of the deaminizing bulb and connections. The Hempel gas pipette is filled with 
the alkaline permanganate solution. 

46 DETERMINATION. 

Fill with water the burette (F), the capillary tube leading to the Hempel pipette 
and also the other capillary as far as c. Introduce into A sufficient glacial acetic 
acid to fill one fifth of D, the tube (A) being etched with a mark to measure this 




pipette 



FIG. 11. DETAILS OF THE DEAMINIZING BULB AND CONNECTION. 

{By courtesy of the Journal of Biological Cheinislry. ) 

amount. Allow the acid to run into D, the cock c being turned so as to allow the 
air to escape from D. Pour the sodium nitrite solution into A until D is full of solu- 
tion and enough excess is present to rise a little above the cock into A. A is also 
marked for measuring off this amount. Then close the gas exit from D at c, and, 
a being open, shake D for a few seconds until the liquid is forced down to the 20 
cc. mark in D. Then close a, open c and shake the apparatus rapidly with the 
motor for 2 minutes, these operations being for the purpose of expelling all the air 
from D. Then turn c and / so that D and F are connected. 



284 METHODS OF ANALYSIS [Chap. 

Measure off in B 10 cc. or less, as the case may be, of the solution of the sample 
containing not more than 20 mg. of amino nitrogen (about 1-2 grams of the sample) 
and allow it to run into D. Connect D with the motor as shown in Fig. 10 and 
shake for 5 minutes. 

If the solution of the sample is viscous and threatens to foam over, rinse out B, 
and then through it introduce a little caprylic alcohol into D, or, if it is known 
beforehand that the sample will cause excessive foaming, introduce a little caprylic 
alcohol into D through B, rinsing B with alcohol and ether or drying with a roll of 
filter paper before adding the solution of the sample. 

During the shaking there is an evolution of nitrogen mixed with nitric oxid,the 
gases being collected in F. Force all the gas in D into F by opening a and filling 
D with liquid from A. Connect F with the Hempel pipette and force the gas into 
the latter by means of the leveling bulb, allowing the cock a to remain open during 
this and the succeeding operation in order to permit displacement of the liquid in 
D by the nitric oxid formed in the interval. Connect the driving rod with the 
pipette by lifting the hook from the shoulder of D and placing the other hook, on 
the opposite side of the driving rod, over the horizontal lower tube of the pipette. 
Shake the pipette rather slowly for a minute which, with any but almost completely 
exhausted permanganate solutions, completes the absorption of nitric oxid. Then 
return the gas to the burette, adjust the level with the leveling bulb and note the 
volume of nitrogen, the temperature and barometric pressure, and calculate the 
volume of nitrogen under standard conditions of temperature and pressure. Ob- 
tain the corresponding weight of nitrogen, divide the latter by 2, and from the 
quotient calculate the apparent per cent of amino nitrogen in the sample. Cor- 
rect the result for a blank test performed as above, using 10 cc. of water instead of 
the solution of the sample. The amount of gas obtained in the blank is usually 
0.3-0.4 cc, and nitrite solutions giving a much larger correction should be 
rejected. 

In the case of beef extracts and similar preparations 5 minutes is sufficient time 
to allow for the completion of the reaction in D. In general the same time serves 
for the decomposition of alpha-amino acids but with ammonia, methylamin and 
most amines other than alpha-amines 1-1^ hours should be allowed. For determi- 
nations on such substances mix the solution of the sample with the reagents as de- 
scribed above, allow the mixture to stand in the apparatus till the end of the re- 
quired time, and conclude the reaction by shaking the apparatus with the motor for 
2-3 minutes. Continue the determination from this point as directed above. 

47 ACID ALCOHOL-SOLUBLE NITROGEN".— TENTATIVE. 

Transfer 10 cc. of an aqueous solution of the sample (10 grams of the sample 
dissolved in sufficient water to make 100 cc.) or, if the sample is insoluble in water, 
1 gram of the sample and 10 cc. of water, to a 200 cc. glass-stoppered measuring 
cylinder, add 1.2 cc. of 12% hydrochloric acid, mix and add absolute alcohol to the 
200 cc. mark. Mix thoroughly and set aside for several hours. If necessary make 
up to volume, filter, transfer 100 cc. of the filtrate to a Kjeldahl flask, evaporate the 
alcohol on a water bath and determine nitrogen in the residue as directed under I, 

18,21 or 23. 

48 CREATIN.— OFFICIAL. 

Dissolve about 7 grams of the sample in cold (20°C.) ammonia-free water in a 
150 cc. beaker, transfer the solution to a 250 cc. measuring flask, dilute to the mark 



XXI] MEAT AND MEAT PRODUCTS 285 

and mix thoroughly. Transfer a 20 cc. aliquot of this solution to a 50 cc. meas- 
uring flask and proceed as directed under 16. Subtract from the combined creati- 
nin value the equivalent of the pre-formed creatinin, 49, and multiply the difference 
by 1.16 to convert into creatin. Express the result as per cent of creatin. 

49 CREATININ.— OFFICIAL. 

For creatinin in beef extract measure about 5 cc. of the solution employed in 48 
into a 500 cc. measuring flask, add 10 cc. of 10% sodium hydroxid solution and 30 
cc. of the saturated picric acid solution (1.2%), mix and rotate for 30 seconds. Allow 
to stand exactly 4| minutes, then dilute to the mark at once with water. Shake 
thoroughly and read the depth of color after standing. If the reading is less than 
7 or over 9.5 mm., repeat, calculating the quantity of solution necessary to obtain a 
reading of about 8 mm. Express the result as per cent of creatinin, making the 
calculations as indicated under 16. 

GLYCEROL. 

50 Cook Method^*.— Tentative. 

Weigh 2 grams of a solid or 5 grams of a liquid preparation in a small lead dish or 
Hofmeister Schalchen containing 20 grams of ignited sand. Transfer the dish and 
its contents to a mortar containing more ignited sand and several grams of anhydrous 
sodium sulphate and mix thoroughly. Transfer the mixture, including the dish, 
to a Soxhlet apparatus which has a piece of cotton placed in the side arm to prevent 
solid particles from being siphoned over. Extract the entire mass with redistilled 
anhydrous acetone for 10 hours. Distil the acetone from the extract, carefully re- 
moving the last trace by means of a vacuum pump. Take up the residue in water, 
add 5 cc. of 10% silver nitrate solution, make up to a volume of 100 cc, shake, allow 
to stand overnight, fllter and determine glycerol in an aliquot of the filtrate as di- 
rected under XIX, 6, beginning at the point "Add * * * 30 cc. of the strong 
potassium dichromate solution". With solid meat and yeast extracts a blank of 
0.5-1.0 % is obtained in most cases. 

51 SUGAR.— TENTATIVE. 

Heat 20 grams of the sample with about 200 cc. of water on a steam bath until all 
soluble substances have gone into solution, cool and proceed from this point as 
directed under 23. Reducing sugar up to 0.5% may be present as a natural con- 
stituent of meat extracts. 

52 PRESERVATIVES.— TENTATIVE. 
Proceed as directed under X. 

53 METALS.— TENTATIVE. 
Proceed as directed under XII. 

54 NITRATES.— TENTATIVE. 
Proceed as directed under 26 or 28. 



286 METHODS OF ANALYSIS 

BIBLIOGRAPHY. 

» J. Assoc. Official Agri. Chemists, 1915, 1 : 230. 
2 J. Am. Chem. Soc, 1906, 28: 1485. 

* J. Assoc. Official Agri. Chemists, 1915, 1: 174. 

* U. S. Bur. Chem. Bull. 162, p. 97. 

6 Abs. Z. Nahr. Hyg. Waar., 1896, 10: 173. 

^ J. Ind. Eng. Chem., 1910, 2: 21, 215. 

^ J. Assoc. Official Agri. Chemists, 1915, 1: 177. 

* Tiemann. Anleitung zur Untersuchung von Wasser. 1870, p. 56; Wiley. Prin- 
ciples and Practice of Agricultural Analysis. 2nd ed., 1906-14, 2:397; U. S. Bur. 
Chem. Bull. 13 (X), p. 1403. 

9 U. S. Bur. Chem. Bull. 13 (X), p. 1405. 

" Allen. Commercial Organic Analysis. 4th ed., 1909-14, 8: 407. 

" Z. anal. Chem., 1895, 34: 562; U. S. Bur. Chem. Bull. 54. 

12 J. Biol. Chem., 1911, 9: 185; 1912, 12: 275; 1913, 16: 121; 1915, 23: 407. 

13 J. Am. Chem. Soc, 1914, 36: 1551. 

" J. Assoc. Official Agri. Chemists, 1915, 1: 279. 



XXII. DAIRY PRODUCTS. 

MILK. 

1 SOLIDS.— OFFICIAL. 

Heat 3-5 grams of the milk at the temperature of boiling water until it ceases 
to lose weight, using a tared, flat-bottomed dish of not less than 5 cm. diameter. 
If desired, previously place 15-20 grams of pure, dry sand in the dish. Cool in a 
desiccator and weigh rapidly to avoid absorption of h3'groscopic moisture. 

2 ASH.— OFFICIAL. 

Weigh about 20 grams of the milk in a tared dish, add 6 cc. of nitric acid, evap- 
orate to dryness and ignite at a temperature just below redness until the ash is free 
from carbon. 

3 TOTAL NITROGEN.— OFFICIAL. 

Place about 5 grams of the milk in a Kjeldahl digestion flask and proceed, without 
evaporation, as directed under I, 18, 21 or 23. Multiplj^ the percentage of nitro- 
gen by 6.38 to obtain the equivalent percentage of nitrogen compounds. 

CASEIN. 

(This determination should be made while the milk is fresh, or nearly so. 

When it is not practicable to make this determination within 

24 hours, add 1 part of formaldehyde to 2500 

parts of milk and keep in a cool place.) 

4 Method I.— Official. 

Place 10 grams of the milk in a beaker with 90 cc. of water at 40°-42°C. and add 
at once 1.5 cc. of 10% acetic acid. Stir and let stand 3-5 minutes. Then decant 
on a filter, wash by decantation 2-3 times with cold water and transfer the precipi- 
tate to the filter. Wash once or twice on the filter. The filtrate should be clear, 
or very nearly so. If the first portions of the filtrate are not clear, repeat the fil- 
tration, after wliich complete the washing of the precipitate. Determine nitrogen 
in the washed precipitate and filter paper as directed under I, 18, 21 or 23, mul- 
tiply by 6.38 and calculate the percentage of casein. 

In samples of milk which have been preserved, the acetic acid should be added 
in small portions, a few drops at a time, with stirring, and the addition continued 
until the liquid above the precipitate becomes clear, or very nearly so. 

5 Method II.— Official. 

To 10 grams of the milk add 50 cc. of water at 40°C., then 2 cc. of alum solution 
saturated at 40°C., or higher. Allow the precipitate to settle, transfer to a filter 
and wash with cold water. Determine nitrogen in the precipitate and filter paper 
as directed under I, 18, 21 or 23, multiply by 6. 38 and calculate the percent- 
age of casein. 

287 



288 



METHODS OF ANALYSIS 



[Chap. 



ALBUMIN. 

6 Method I. — Tentative. 

Exactly neutralize the filtrate, obtained in 4, with sodium hydroxid solution, 
add 0.3 cc. of 10% acetic acid and heat on a steam bath until the albumin is com- 
pletely precipitated. Collect the precipitate on a filter, wash with cold water and 
determine the nitrogen as directed under I, 18, 21 or 23, multiply by 6.38 and cal- 
culate the percentage of albumin. 

7 Method II. — Tentative. 

To the filtrate obtained from the casein determination, 5, add 0.3 cc. of 10% acetic 
acid, boil until the albumin is completely precipitated and proceed as directed in 6. 



8 



LACTOSE. 
Optical Method. — Tentative. 

REAGENTS. 



(a) Acid mercuric nitrate solution. — Dissolve mercury in double its weight of 
nitric acid (sp. gr. 1.42) and dilute with an equal volume of water. 

(b) Merctiric iodid solution. — Dissolve 33.2 grams of potassium iodid and 13.5 
grams of mercuric chlorid in 20 cc. of glacial acetic acid and 640 cc. of water. 



9 



DETERMINATION. 



Determine the specific gravity of the milk by means of a delicate hydrometer 
or, if preferred, a pycnometer. The quantity of sample to be taken for the deter- 
mination varies with the specific graA^ty and is to be measured at the same tempera- 
ture at which the specific gravitj'^ is taken. The volume to be measured will be 
found in 10 which is based upon twice the normal weight of lactose (32.9 grams per 
100 metric cc.) for the Ventzke sugar scale. 

Place the quantity of milk indicated in 10 in a flask graduated at 102.6 cc. Add 
1 cc. of the acid mercuric nitrate solution or 30 cc. of the mercuric iodid solution 
(an excess of these reagents does no harm), fill to the mark, shake, filter through a 
dry filter and polarize. It is not necessary to heat before polarizing. If a 200 mm. 
tube is used, divide the polariscope reading by 2 (or, if a 400 mm. tube is used, by 4) 
to obtain the per cent of lactose in the sample. 



10 



Table 19- 
Volumes of milk corresponding to a lactose double normal weight^. 





VOLUME OF MILK FOR A 




VOLUME OF MILK FOR A 


SPECIFIC GRAVITr OF 


LACTOSE DOUBLE NOR- 


SPECIFIC GR.VVITY OF 


LACTOSE DOUBLE NOR- 


MILK 


MAL WEIGHT 


MILK 


MAL WEIGHT 




(VENTZKE scale) 




(ventzke sc.\le) 




CC. 




CC. 


1.024 


64.25 


1.030 


63.90 


1.025 


64.20 


1.031 


63.80 


1.026 


64.15 


1.032 


63.75 


1.027 


64.05 


1.033 


63.70 


1.028 


64.00 


1.034 


63.65 


1.029 


63.95 


1.035 


63.55 






1.036 


63.50 



XXII] DAIRY PRODUCTS 289 

1 1 Gravimetric Method. — Official. 

Dilute 25 grams of the milk with 400 cc. of water in a 500 cc. graduated flask, 
add 10 cc. of copper sulphate solution [VIII, 19 (a)] and about 7.5 cc. of a potas- 
sium hydroxid solution of such strength that 1 volume is just sufficient to pre- 
cipitate completely the copper as hydroxid from 1 volume of the copper sulphate 
solution. Instead of potassium hydroxid solution of this strength, 8.S cc. of N/2 
sodium hydroxid solution may be used. After the addition of the alkali solution 
the mixture must still have an acid reaction and contain copper in solution. Fill 
the flask to the 500 cc. mark, mix, filter through a dry filter and determine lactose 
in an aliquot of the filtrate as directed under VIII, 46 or 48. 

FAT. 

12 Roese-Gottlieb Method^— Official. 

Weigh 10-11 grams of the milk into a Rohrig tube or some similar apparatus, 
add 1.25 cc. of concentrated ammonium hydroxid (2 cc. if the sample is sour) and 
mix thoroughly. Add 10 cc. of 95% alcohol by volume and mix well. Then add 
25 cc. of washed ether and shake vigorously for 30 seconds, then 25 cc. of petro- 
leum ether (redistilled slowly at a temperature below 60°C.) and shake again for 
30 seconds. Let stand 20 minutes, or until the upper liquid is practically clear. 
Draw off as much as possible of the ether-fat solution (usually 0.5-0.8 cc. will be left) 
into a weighed flask through a small, quick-acting filter. The flask should always 
be weighed with a similar one as a counterpoise. Re-extract the liquid remain- 
ing in the tube, this time with only 15 cc. of each ether, shake vigorously 30 seconds 
with each and allow to settle. Draw off the clear solution through the small filter 
into the same flask as before and wash the tip of spigot, the funnel and the filter 
with a few cc. of a mixture of the 2 ethers in equal parts. For absolutely exact 
results the re-extraction must be repeated. This third extraction yields usually 
not more than about 1 mg. of fat (about 0.02% on a 4 gram charge) if the previous 
ether-fat solutions have been drawn off closely. Evaporate the ethers slowly on a 
steam bath, then dry the fat in a boiling water oven to constant weight. 

Confirm the purity of the fat by dissolving in a little petroleum ether. Should 
a residue remain, remove the fat completely with petroleum ether, dry the residue, 
weigh and deduct the weight. Finally correct this weight bj^ a blank determina- 
tion on the reagents used. 

Babcock Method. — Official. 

13 APPARATUS. 

(a) Standard Babcock test bottles.~The standard Babcock test bottles for milk 
and cream shall be as follows : 

(1) 8%, 18 gram, 6 inch milk test bottle.— The total per cent graduation shall be 8. 
The total height of the bottle shall be 150-165 mm. (5f-6| inches). The capac- 
ity of the bulb up to the junction with the neck shall be not less than 45 cc. The 
graduated portion of the neck shall have a length of not less than 63.5 mm. (2^ 
inches) and the neck shall be cylindrical for at least 9 mm. below the lowest and 
above the highest graduation marks. The graduations shall represent whole per 
cents, halves and tenths of a per cent. 

(2) 50%, 9 gram, 6 inch cream lest bottle.— The total per cent graduation shall 
be 50. The total height of the bottle shall be 150-165 mm. (5|-6^ inches). The 
capacity of the bulb up to the junction with the neck shall be not less than 45 cc. The 
graduated portion of the neck shall have a length of not less than 63.5 mm. (2^ 



290 METHODS OF ANALYSIS [Chap. 

inches) and the neck shall be cylindrical for at least 9 mm. below the lowest and 
above the highest graduation marks. The graduations shall represent five per cents, 
whole and halves of a per cent. 

(3) 50%, 9 gram, 9 inch, cream test bottle: — Same as (2) except that the total height 
of the bottle shall be 210-225 mm. {8iSl inches). 

(b) Centrifuge. 

(C) Pipettes. — Graduated to deliver 17.6 cc. of water at 20°C. in 5-8 seconds. 

(d) Graduates. — Capacity 17.5 cc. or a Swedish acid bottle delivering that amount. 

14 CALIBRATION" OF APPARATUS. 

(a) Graduation. — The unit of graduation for all Babcock glassware shall be the 
true cc. (0.99SS77 gram of water at 4°C.). 

With bottles, the capacity of each per cent on the scale shall be 0.20 cc. 

With pipettes and graduates, the delivery shall be the intent of the graduation; 
and the graduation shall be read with the bottom of the meniscus in line with the 
mark. 

(b) Testing. — The method for testing Babcock bottles shall be calibration with 
mercurj' (13.5471 grams of clean, dry mercury at 20°C., to be equal to 5% on the 
scale), the bottle being previously filled to zero with mercury. 

The mercury and cork, alcohol and burette, and alcohol and brass plunger 
methods may be employed for the rapid testing of Babcock bottles, but the accuracy 
of all questionable bottles shall be determined by calibration with mercury. 

The method for testing pipettes and graduates shall be calibration by measuring 
in a burette the quantity of water (at 20°C.) delivered. 

(C) Limit of error. — For standard Babcock milk bottles the error at any point 
of the scale shall not exceed 0.1%. 

For standard Babcock cream bottles the error at any point of the scale shall not 
exceed 0.5 %. 

For standard milk pipettes the error shall not exceed 0.05 cc. 

For acid measures the error shall not exceed 0.2 cc. 

15 DETERMIXATIOX. 

Pipette 17.6 cc. of the carefulh' mixed sample into a test bottle and add 17.5 
cc. of commercial sulphuric acid (sp. gr. 1.S2-1.S3'. Mix and, when the curd is 
dissolved, ccntrifugalize for 4 minutes at the required speed for the machine used. 
Add boiling water, filling to the neck of the bottle, and whirl for 1 minute; again 
add boiling water so as to bring the fat within the scale on the neck of the bottle, 
and, after whirling for 1 minute more, read the length of the fat column, making the 
reading at 57°-60°C. at which temperature the fat is wholly liquid. The reading 
gives directly the per cent of fat in the milk. 

Details of the manipulation of the Babcock test and its application in the analy- 
sis of dairv products other than milk are described by Farrington and WoU', and 
Van Slyke^ 

Added Water. 

(In conjunction with the copper, acetic or sour serum refraction method, 

the determination of the ash of the sour serum or of the acetic serum 

should be made in all cases where the indices of refraction 

fall below the minimum limit so as to eliminate 

all possibility of abnormal milk.) 



XXn] DAIRY PRODUCTS 291 

16 ACETIC SERUM.-TENTATIVE. 

(a1 Zeiss immersion refractometcr reading.— To 100 ec. of milk at a temperature 
of about 20''C. add 2 cc. of 25% acetic acid (sp. gr. 1.035) in a beaker and heat the 
mixture, covered with a watch ghiss, in a water bath for 20 minutes at a tempera- 
ture of TO^'C. Place the beaker on ice water for 10 minutes and separate the curd 
from the serum by filtering through a 12.5 cm. folded filter. Transfer about 3;') cc. 
of the serum to 1 of the beakers that accompanies the control-temperature bath 
used in connection with the Zeiss immersion refractometcr, and take the ref lac- 
tometer reading at exactly 20^C., using a thermometer graduated to tenths of a 
degree. A reading below 30 indicates added water; between 30 and 40, the addition 
of water is suspected. 

(b) Ash. — Transfer 25 cc. of the serum to a flat-bottomed platinum dish and 
evaporate to drj^ness on a water bath. Then heat over a low flame (to avoid spat- 
tering) until the contents are thoroughly charred, place the dish in an electric 
muffle, preferably with pyrometer attached, and ignite to a white ash at a tem- 
perature not greater than o00°C. (900°F.). Cool and weigh. Express the result 
as grams per 100 cc. Results below 0.715 gram per 100 cc. indicate added water. 
Multiply by the factor 1.021 (dilution of the acetic serum being 2%) to obtain the 
result on the sour serum ash. 

1 7 SOUR SERUM.-TENTATIVE. 

(a) Zeiss immersion refractometcr reading. — Allow the milk to sour spontane- 
ously, filter and determine the immersion refractometer reading of the clear serum 
at 20°C. A reading below 3S.3 indicates added water. 

(b) Ash^. — Determine the ash in 25 cc. of the serum, obtained in (a), as directed 
in 16 (b). Kesults below 0.730 gram per 100 cc. indicate added water. 

18 ZEISS REFRACTOMETER READING OF COPPER SERUM.-TENTATIVE. 

To 1 volume of copper sulphate solution (72.5 grams of copper sulphate per 
liter, adjusted if necessary to read 36 at 20°C. on the scale of the Zeiss immersion 
refractometcr, or, to a specific gravity of 1.0443 at ^^-43—") add 4 volumes of milk. 
Shake well and filter. Determine the Zeiss refractometer reading of the clear 
serum at 20''C. A reading below 3G indicates added water. 

GELATIN. 

19 Qualitative Test. — Tentative. 

To 10 cc. of the milk add an equal volume of acid mercuric nitrate solution (mer- 
cury dissolved in twice its weight of nitric acid (sp. gr. 1.42) and this solution 
diluted to 25 times its volume with water), shake the mixture, add 20 cc. of water, 
shake again, allow to stand 5 minutes and filter. If much gelatin is present, the 
filtrate will be opalescent and cannot be obtained quite clear. To a portion of the 
filtrate contained in a test tube, add an equal volume of saturated aqueous picric 
acid solution. A yellow precipitate will be produced in the presence of any con- 
siderable amount of gelatin, while smaller amounts will be indicated by a cloudi- 
ness. In the absence of gelatin the filtrate will remain perfectly clear. 

20 PRESERVATIVES.— TENTATIVE. 

Proceed as directed under X. To test for salicj^lic or benzoic acid acidify 100 
cc. of the milk with 5 cc. of hydrochloric acid (1 to 3), shake until curdled, filter 
and treat the clear filtrate as directed under X, 2, 3 or 8. 



292 METHODS OF ANALYSIS [Chap. 

To test for formaldehyde proceed as directed under X, 17, 18, 19, 20, 21, 22, 
or 23, applying the test directly to the milk. 

COLORING MATTERS. 

21 Leach Method. — Tentative. 

Warm about 150 cc. of milk in a casserole over a flame and add about 5 cc. of 
acetic acid, then slowly continue the heating nearly to the boiling point while stir- 
ring. Gather the curd, when possible, into one mass with a stirring rod and pour 
off the whey. If the curd breaks up into small flecks, separate from the whey by 
straining through a sieve or colander. Press the curd free from adhering liquid, 
transfer to a small flask and macerate for several hours, preferably overnight, in 
about 50 cc. of ether, the flask being tightly corked and shaken at intervals. De- 
cant the ether extract into an evaporating dish, remove the ether by evaporation 
and test the fatty residue for annatto as directed in XI, 24. 

The curd of an uncoloredmilk is perfectly white after complete extraction with 
ether, as is also that of a milk colored with annatto. If the extracted fat-free curd 
is distinctly colored an orange or yellowish color, a coal tar dye is indicated. In 
many cases upon treating a lump of a fat-free curd in a test tube with a little strong 
hydrochloric acid the color changes to pink, indicating the presence of a dye simi- 
lar to aniline yellow or butter yellow or perhaps one of the acid azo yellows or 
oranges. In such cases, separate and identify the coloring matter present in the 
curd as directed under XI. If aniline yellow, butter yellow, or other oil-soluble 
dye is present, the greater part will be found in the ether extract containing the 
fat. In such cases proceed as directed under XI, 3. 

In some cases the presence of coal tar dyes can be detected by treating about 
10 cc. of the milk directly with an equal volume of hydrochloric acid (sp. gr. 1.20) 
in a porcelain casserole, giving the dish a slight rotary motion. In the presence of 
some dyes the separated curd acquires a pink coloration. 

CREAM. 

22 SOLIDS.-OFFICIAL. 

Proceed as directed in 1, employing 2-3 grams of the sample. 

23 ASH.— OFFICIAL. 
Proceed as directed under 2. 

24 TOTAL NITROGEN.— OFFICIAL. 

Proceed as directed under 3. 

LACTOSE. 

25 Gravimetric Method. — Official. 

Proceed as directed under 1 1 . 

FAT. 

26 E.ttraction Method. — Official. 

Weigh 4-5 grams of the homogeneous sample into a Rohrig tube or similar appa- 
ratus, dilute with water to about 10.5 cc. and proceed as directed under 12. 

27 Babcock Method. — Official. 

Weigh 9 or 18 grams, depending upon the fat content of the sample, into a stand- 
ard Babcock cream bottle and proceed as directed under 15. 



XXn] DAIRY PRODUCTS 293 

28 GELATIN.— TENTATIVE. 
Proceed as directed under 19. 

29 COLORING MATTERS.— TENTATIVE. 

Proceed as directed under XI, particularly 3 and 24 for the detection of oil- 
soluble coal tar dyes and annatto. 

30 PRESERVATIVES.-TENTATIVE. 
Proceed as directed under X. 

31 CONDENSED MILK (UNSWEETENED). 

Dilute 40 grams of the homogeneous sample with 60 grams of water and pro- 
ceed as directed under 1 to 15, inclusive, 19, 20 and 21, correcting the results for 
the dilution. 

CONDENSED MILK (SWEETENED). 

32 PREPARATION OF SAMPLE.— OFFICIAL. 

If cold, place the can in water at 30°-35°C. until warm. Open, scrape out all 
milk adhering to the interior of the can and mix by transferring the contents to a 
dish sufficiently large to stir thoroughly and make the whole mass homogeneous. 
Weigh 100 grams into a 500 cc. flask and make up to the mark with water. If the 
milk will not dissolve completely, weigh out each portion for analysis separately. 

33 TOTAL SOLIDS.— OFFICIAL. 

Use 10 cc. of the solution, prepared as directed in 32, and proceed as directed in 
1 , drying either on sand or asbestos fiber. 

34 ASH.-OFFICIAL. 

Evaporate 10 cc. of the solution, prepared as directed in 32, to dryness on a 
water bath and ignite the residue as directed under VIII, 4. 

35 PROTEIN.— OFFICIAL. 

Determine nitrogen as directed under I, 18, 21 or 23, using 10 cc. of the solu- 
tion, prepared as directed in 32, without evaporation and multiply by 6.38. 

36 LACTOSE.— OFFICIAL. 

Dilute 100 cc. of the solution, prepared as directed in 32, in a 250 cc. flask to 
about 200 cc, add 6 cc. of Fehling's copper sulphate solution [VIII, 19 (a)] and make 
up to the mark. Filter through a dry filter and determine lactose as directed in 

VIII, 46 or 48. 

37 FAT OR ETHER EXTRACT. 

Roese-Gotilieb Method. — Official. 

Weigh 4-5 grams of the homogeneous sample into a Rohrig tube or some similar 
apparatus, dilute with water to about 10.5 cc. and proceed as directed under 12. 

38 SUCROSE.— TENTATIVE. 

Determine sucrose by difference, deducting the milk solids (lactose, protein, fat 
and ash) from the total solids. 



294 METHODS OF ANALYSIS [Chap. 

BUTTER AND ITS SUBSTITUTES. 

39 PREPARATION OF SAMPLE. -OFFICIAL. 

If large quantities of batter are to be sampled, use a butter trier or sampler. 
Melt completely the portions thus drawn, 100-500 grams, in a closed vessel at as 
low a temperature as possible. When softened, cool and, at the same time, shake 
the mass violently until it is homogeneous and solidified sufBcicntly to prevent the 
separation of the water and fat. Then pour a portion into the vessel from which 
it is to be weighed. The sample should completely or nearly fill the vessel and 
should be kept in a cool place until analyzed. 

40 MOISTURE.— OFFICIAL. 

Weigh 1.5-2.5 grams of the sample into a flat-bottomed dish, having a surface 
of at least 20 sq. cm., dry at the temperature of boiling water and weigh at hourly 
intervals until the weight becomes constant. The use of clean, dry sand or asbestos 
is admissible. 

ETHER EXTRACT. 

41 Indirect Method. — Official. 

Dissolve the dry butter, obtained in the moisture determination in which no 
absorbent was used, in absolute ether or petroleum ether, transfer to a weighed 
Gooch, with the aid of a wash bottle filled with the solvent and wash until free 
from fat. Dry the Gooch and contents at the temperature of boiling water until 
the weight is constant and determine the fat. 

42 Direct Method.— Official. 

From the dry butter, obtained in the determination of moisture, either with or 
without the use of an absorbent, extract the fat with anhydrous, alcohol-free ether, 
receiving the solution in a weighed flask. Evaporate the ethor, dry the extract at 
the temperature of boiling water and weigh at hourly intervals until the weight 
is constant. 

43 CASEIN, ASH AND CHLORIN.— OFFICIAL. 

Cover the crucible, containing the residue from the fat determination by the 
indirect met hod, 41 , and heat gently at first, then raise the temperature gradually 
to just below redness. The cover may then be removed and heating continued 
until the contents of the crucible are white. The loss in weight represents casein, 
and the residue in the crucible, mineral matter. Dissolve this mineral matter in 
water slightly acidified with nitric acid and determine chlorin, either graviraetri- 
cally as directed under I, 16 (a), or volumetrically as directed under III, 15. 

44 SALT.-OFFICIAL. 

Weigh in a counterpoised beaker 5-10 grams of butter, using portions of about 
1 gram from dift'erent parts of the sample. Add about 20 cc. of hot water and, after 
the butter is melted, transfer the whole to a separatory funnel. Insert the stopper 
and shake for a few moments. Let stand until all the fat has collected on the top 
of the water, then draw oiT the latter into a flask, being careful to let none of the 
fat globules pass. Again add hot water, rinsing the beaker, and repeat the extrac- 
tion 10-15 times, using 10-20 cc. of water each time. The washings will contain all 
but a mere trace of the sodium chlorid originally present in the butter. Determine 
the amount in the whole or an aliquot of the liquid by titration with standard silver 
nitrate, using potassium chromate as an indicator. 



xxii] dairy products 295 

Fat. 

45 preparation of sample.— official. 

Melt the butter and keep in a dry place at about 60°C. for 2-3 hours or until the 
water and curd have entirely separated. Filter the clear, supernatant fat through 
a dry filter paper in a hot water funnel or in an oven at about 60°C. If the filtered 
liquid fat is not perfectly clear, refilter. 

46 EXAMINATION. 
Proceed as directed under XXIII. 

47 Microscopic Method. — Official. 

Place on a slide a small portion of the fresh, unmelted sample taken from the 
inside of the mass, add a drop of pure olive oil, apply a cover-glass with gentle 
pressure, and examine with a magnification of 120-150 diameters for crystals of 
lard, etc. Examine the same specimen with polarized light and a selenite plate 
without the use of oil. Pure fresh butter will show neither crystals nor a parti- 
colored field with selenite. Renovated butter or other fats melted and cooled and 
mixed with butter will usually present crystals and variegated colors with the 
selenite plate. 

For further microscopic study dissolve in a test tube 3-4 cc. of the fat in 15 cc. 
of ether. Close the tube with a loose plug of cotton wool and allow to stand 12-24 
hours at 20°-25°C. When crystals form at the bottom of the tube, remove with a 
pipette, glass rod or tube, place on a slide, cover and examine under a microscope. 
The crystals formed by later deposits may be examined in a similar way. Com- 
pare with crystals obtained in the same way from samples of known purity. 

48 PRESERVATIVES.— TENTATIVE. 

Proceed as directed under X. > 

49 COLORING MATTERS.— TENTATIVE. 

Pour about 2 grams of the filtered fat, dissolved in ether, into each of 2 test tubes. 
Into one of the tubes pour 1-2 cc. of hydrochloric acid and into the other about the 
same volume of dilute potassium hydroxid solution. Shake the tubes well and 
allow to stand. In the presence of azo dyes the test tube to which the acid has been 
added will show a pink to wine-red coloration, while the potash solution in the 
other tube will show no color. If, on the other hand, annatto or other vegetable 
color has been used, the potash solution will be colored yellow, while no color will 
be apparent in the acid solution. 

General test. — Proceed as directed under XI, particularly 3 and 24, for the detec- 
tion of oil-soluble coloring matters and annatto. 

RENOVATED BUTTER AND OLEOMARGARINE. 

50 Foam Test. — Tentative. 

Heat 2-3 grams of the sample, either in a spoon or dish, over a free flame. True 
butter will foam abundantly, whereas process butter will bump and sputter, like 
hot grease, without foaming. Oleomargarine behaves like process butter, but 
chemical tests will determine whether the sample is oleomargarine or butter. 



296 METHODS OF ANALYSIS [Chap. 

51 Melted Fat Test.— Tentative. 

Melt 50-100 grams of butter or renovated butter at 50°C. The curd from butter 
will settle, leaving a clear supernatant fat; in the case of renovated butter, the 
supernatant fat remains more or less turbid. 

CHEESE. 

52 SELECTION AND PREPARATION OF THE SAMPLE.— OFFICIAL. 

When the cheese can be cut, take a narrow, wedge-shaped segment reaching 
from the outer edge to the center of the cheese. Cut this into strips and pass 3 
times through a sausage machine. When the cheese cannot be cut, take the sample 
with a cheese trier. If only 1 plug can be obtained, take it perpendicular to the 
surface of the cheese at a point one third the distance from the edge to the center 
and extending either entirely or half way through it. When possible, draw 3 plugs, 
1 from the center, 1 from a point near the outer edge, and 1 from a point half way 
between the other 2. For inspection purposes reject the rind but for investigations 
requiring the absolute amount of fat in the cheese include the rind in the sample. 
Either grind the plugs in a sausage machine or cut them very finely and mix carefully, 
preferably the former. 

53 MOISTURE.— TENTATIVE. 

Place 2-3 grams of very short fiber asbestos (the long fiber may be made suit- 
able by rubbing it through a fine sieve) in a flat-bottomed platinum dish, 6-7 cm. 
in diameter, and press the asbestos down firmly. Place in the dish a glass rod, 
about 5 mm. in diameter and slightly longer than the diameter of the dish. Ignite, 
cool and weigh the dish and contents. Then weigh into the dish 4-5 grams of the 
sample, prepared as directed under 52, and mix the cheese and asbestos intimately 
with the glass rod until the mass is homogeneous. Leave the mass in as loose a con- 
dition as possible to facilitate the drying. Dry the mixture in an oven at 100°C. 
and weigh at 1-1| hour intervals until the weight becomes constant (3 weighings are 
usually sufficient). 

54 ASH AND SALT.— OFFICIAL. 

The dry residue from the moisture determination may be used for the determi- 
nation of ash. If the cheese be rich in fat, the asbestos will be saturated with it. 
Ignite cautiously to avoid spattering and remove the lamp while the fat is burn- 
ing off. When the flame has died out, complete the bm-ning in a mufiie at low red- 
ness. When desired, the salt may be determined in the ash, as directed in 43. 

55 NITROGEN.— OFFICIAL. 

Determine nitrogen as directed under I, 18, 21 or 23, using about 2 grams of 
cheese, and multiply the percentage of nitrogen by 6.38 to obtain the per cent 
of nitrogen compounds. 

56 ACIDITY.— TENTATIVE. 

To 10 grams of finely divided cheese add water at a temperature of 40°C. until 
the volume equals 105 cc, shake vigorously and filter. Titrate 25 cc. portions of 
the filtrate, representing 2.5 grams of the sample, with standard sodium hydroxid, 
preferably N/10, using phenolphthalein as an indicator. Express the result in 
terms of lactic acid. 



XXII] DAIRY PRODUCTS 297 

57 COLORING MATTERS.— TENTATIVE. 
Proceed as directed under XI. 

Fat. 

58 preparation of sample.— tentative. 

(a) Alkaline extraction. — Treat about 300 grams of the cheese, cut into frag- 
ments the size of a pea, with 700 cc. of 5% potassium hydroxid solution at 20°C. in 
a large, wide-necked flask, shaking vigorously to dissolve the casein. In 5-10 
minutes the casein will be dissolved and the fat will rise to the surface in limips. 
Collect the liunps of fat into as large a mass as possible by shaking gently. Pour 
cold water into the flask until the fat is driven up into the neck and remove it by 
suitable means. Wash the fat thus obtained with just sufficient water to remove 
the residue of the alkali which it may contain. The fat is not perceptibly attacked 
by the alkali in this treatment, is practically all separated in a short time and is then 
easily prepared for chemical analysis by filtering and drying as directed in 45. 

(b) Acid extraction. — Pass the cheese through a grinding machine, transfer to a 
large flask and cover with warm water, using 1 cc. for every gram of cheese. Shake 
thoroughly and add sulphuric acid (sp. gr. 1.82-1.825) slowly and in small quanti- 
ties, shaking after each addition of acid. The total amount of acid used should 
be the same as the amount of water employed. Remove the fat, which separates 
after standing a few minutes, by means of a separatory funnel, wash free from acid, 
filter and dry as directed in 45. 

59 examination.— tentative. 
Proceed as directed under XXIII. 

Estimation. 

60 Gravimetric Method. — Official. 

Cover the perforations in the bottom of an extraction tube with dry asbestos 
felt, and place on this a mixture containing equal parts of anhydrous copper sul- 
phate and pure, dry sand to a depth of about 5 cm., packing loosely. Cover the 
upper surface of this material with a layer of asbestos. Place on this 2-5 grams of 
the sample and extract with anhydrous ether for 5 hours in a continuous extrac- 
tion apparatus. Remove the cheese and grind it with pure sand in a mortar to a 
fine powder, return the mixed cheese and sand to the extraction tube, wash the mor- 
tar with ether, add the washings to the tube and continue the extraction for at least 
10 hours. 

61 Schmidt-Bondzynski Method, Modified. — Tentative. 

Rub up, by means of a glass rod, 1 gram of the homogeneous sample with 9 cc. of 
water and 1 cc. of concentrated ammonium hydroxid in a narrow 100-125 cc. beaker. 
Digest the mixture at a low heat until the casein is well softened; neutralize with 
concentrated hydrochloric acid, using litmus as an indicator and add 10 cc. more 
of concentrated hydrochloric acid. Add a pinch of sand to prevent bumping and 
boil gently for 5 minutes, keeping the beaker covered with a watch glass. Cool 
the solution, transfer to a Rohrig tube or some similar apparatus, rinse the beaker 
with 25 cc. of washed ethyl ether and shake well. Add 25 cc. of redistilled petro- 
leum ether (b. p. below 65°C.), let the solutions separate and proceed from this 
point as directed in 12. 



298 METHODS OF ANALYSIS 

62 Babcock Method. — Tentative. 

Weigh about 6 grams of the cheese in a tared dish. Add 10 cc. of boiling water and 
stir with a rod until the cheese softens and an even emulsion is formed, preferably 
adding a few drops of strong ammonium hydroxid, and keep the beaker in hot water 
until the emulsion is nearly completed and the mass free from lumps. If the sample 
is a whole milk cheese, employ a Babcock cream bottle. After cooling, transfer the 
contents of the beaker to the test bottle by adding to the beaker about half of the 
17.6 cc. of sulphuric acid usually employed in this test, stirring with a rod, and 
pouring carefully into the bottle, using the remainder of the acid in 2 portions for 
washing out the beaker. Then proceed as directed in 15. Multiply the fat reading 
by 18 and divide by the weight of the sample taken to obtain the per cent of fat. 

BIBLIOGRAPHY. 

1 Browne. Handbook of Sugar Analysis. 1912, p. 252. 

2 Z. Nahr. Genussm., 1905, 9: 531. 

3 Farrington and Woll. Testing Milk and Its Products. 23rd ed., 1916. 

^-Van Slyke. Modern Methods of Testing Milk and Milk Products. Rev. ed., 
1907. 

sChem. Ztg., 1908, 32:617. 



XXIII. FATS AND OILS. 

1 PREPARATION OF SAMPLE.— OFFICIAL. 

Melt solid fats and filter by means of a hot water funnel or similar apparatus. 
Make the different determinations on samples of this melted, homogeneous mass. 
Filter oils that are not clear. Keep oils and fats in a cool place and protected from 
light and air, otherwise they will soon become rancid. Weigh out at one time as 
many portions as are needed for the various determinations, using a small beaker 
or weighing burette. 

SPECIFIC GRAVITY. 

2 20°C. „ 
At Tentative. 
4° 

OQOQ 

Determine the specific gravity of the oil at "-^ by means of a pycnometer. 
If the specific gravity of the oil is determined at other than standard tempera- 
ture, the approximate specific gravity at 20°C. may be calculated by means of the 
following formula: 

G = G' + 0.0007 (T-20°C.) in which 
G = specific gravity at 20°C. ; 

T°C 

G' = specific gravity at -jr-' ; 

T = temperature at which the specific gravity was determined; 
0.0007 = mean correction^ for 1°C. 

At the Temperature of Boiling Water.— Official. 

3 STANDARDIZATION OF FLASKS. 

(a) Fill a tared, 25-30 cc. specific gravity flask with freshly boiled, hot water. 
Place in a briskly boiling water bath for 30 minutes, replacing any evaporation 
from the flask by the addition of boiling water. Then insert the stopper, previous- 
ly heated to 100°C., remove the flask, cool and weigh. 

(b) The following formula may be used for calculating the weight of water (VV^) 
which a given flask will hold at T° (weighed in air with brass weights at the tempera- 
ture of the room) from the weight of water (W*) (weighed in air with brass weights 
at the temperature of the room) contained therein at t°: 

W^ = W* -JT [1 + 0.000026 (T - t)] in which 
d"^ 

d'' = the density of water at T°; 

d* = the density of water at t°. 

4 DETERMINATION. 

Fill the flask, dried at the temperature of boiling water, with the dry, hot, freshly 
filtered fat, which should be entirely free from air bubbles; keep in the water bath 
30 minutes at the temperature of boiling water. Insert the stopper, previously 
heated to 100°C., cool and weigh. Divide the weight of contained fat by the weight 
of contained water previously found to obtain the specific gravity. 

The weight of water at boiling temperature must be determined under the baro- 
metric conditions prevailing at the time the determination is made. 

299 



300 METHODS OF ANALYSIS [Chap. 

INDEX OF REFRACTION. 
5 General Directions.— Tentative. 

Place the instrument in such a position that diffuse daylight or any form of arti- 
ficial light can readily be obtained for illumination. Circulate through the prisms 
a stream of water of constant temperature. 

Determine the index of refraction with any standard instrument, reading oils at 
20°C. and fats at 40°C. 

The readings of the Zeiss butyro-refractometer can be reduced to standard tem- 
perature by the following formula^: 

R = R' + 0.55 (T' - T) in which 
R = the reading reduced to temperature T; 
R' = the reading at T'C. 

T' = the temperature at which reading R' is made; 
T = the standard temperature; 
0.55 = correction in scale divisions for 1°C. 
With oils the factor 0.58 is substituted in the formula for 0.55, since they have a 
higher index of refraction. 

The readings of instruments, which give the index of refraction directly, can be 
reduced to standard temperature by substituting the factor 0.000365 for 0.55 in the 
formula. As the temperature rises the refractive index falls. 

The instrument used may be standardized with water at 20°C., the theoretical 
refractive index of water at that temperature being 1.3330. Any correction found 
should be made on all readings. 

The index of refraction varies directly with the specific gravity. If the results 
appear abnormal, compare the specific refractive power' with the normal. Calcu- 

N - 1 
late the specific refractive power from the formula — — — , in which N equals 

the refractive index and D the specific gravity. According to Procter* the Lorenz 
N2 — 1 . N — 1 

formula gives much more satisfactory results than — — — . 

(N^ + 2) D D 

R By Means of the Abbe Refractometer.— Official. 

To charge the instrument, open the double prism by means of the screw head 
and place a few drops of the sample on the prism or, if preferred, open the prisms 
slightly by turning the screw head and pour a few drops of the sample into the 
funnel-shaped aperture between the prisms. Then close the prisms firmly by 
tightening the screw head. Allow the instrument to stand for a few minutes 
before the reading is made, so that the temperature of the sample and the instru- 
ment will be the same. 

The method of measurement is based upon the observation of the position of the 
border line of total reflection in relation to the faces of a prism of flint glass. Bring 
this border line into the field of vision of the telescope by rotating the double prism 
by means of the alidade in the following manner: Hold the sector firmly, move the 
alidade backward or forward until the field of vision is divided into a light and a 
dark portion. The line dividing these portions is the "border line". This, as a 
rule, will not be a sharp line but a band of color which is eliminated by 
rotating the screw head of the compensator until a sharp, colorless line is obtained. 
The border line should now be adjusted so that it falls on the point of intersection 
of the 2 cross hairs. Read the refractive index of the substance directly on the 
scale of the sector. Check the correctness of the instrimaent, as directed under 5, 
or by means of the quartz plate which accompanies it, using monobromnaphtha- 
lene, and make the necessary correction in the reading. 



xxmi 



FATS AND OILS 



301 



7 By Means of the Zeiss Butyro-Refractometer.— Official. 

Place 2 or 3 drops of the filtered fat on the surface of the lower prism. Close the 
prisms and adjust the mirror until it gives the sharpest reading. If the reading 
be indistinct after running water of a constant temperature through the instru- 
ment for some time, the fat is unevenly distributed on the surfaces of the prism. 
As the index of refraction is greatly affected by temperature, care must be used to 
keep the latter constant. The instrument should be carefully adjusted by means of 
the standard fluid which is supplied with it. Convert the degrees of the instru- 
ment into refractive indices from 8. 



8 



Table 20. 
Butyro-ref Tactometer readings and indices of refraction. 



BEADING 


INDEX OF 
REFRACTION 


READING 


INDEX OF 
REFR.4.CTION 


READING 


INDEX OF 
REFR.4.CTION 


READING 


INDEX OF 
REFRACTION 


40.0 


1.4524 


50.0 


1.4593 


60.0 


1.4659 


70.0 


1.4723 


40.5 


1.4527 


50.5 


1.4596 


60.5 


1.4662 


70.5 


1.4726 


41.0 


1.4531 


51.0 


1.4600 


61.0 


1.4665 


71.0 


1.4729 


41.5 


1.4534 


51.5 


1.4603 


61.5 


1.4668 


71.5 


1.4732 


42.0 


1.4538 


52.0 


1.4607 


62.0 


1.4672 


72.0 


1.4735 


42.5 


1.4541 


52.5 


1.4610 


62.5 


1.4675 


72.5 


1.4738 


43.0 


1.4545 


53.0 


1.4613 


63.0 


1.4678 


73.0 


1.4741 


43.5 


1.4548 


53.5 


1.4616 


63.5 


1.4681 


73.5 


1.4744 


44.0 


1.4552 


54.0 


1.4619 


64.0 


1.4685 


74.0 


1.4747 


44.5 


1.4555 


54.5 


1.4623 


64.5 


1.4688 


74.5 


1.4750 


45.0 


1.4558 


55.0 


1.4626 


65.0 


1.4691 


75.0 


1.4753 


45.5 


1.4562 


55.5 


1.4629 


65.5 


1.4694 


75.5 


1.4756 


46.0 


1.4565 


56.0 


1.4633 


66.0 


1.4697 


76.0 


1.4759 


46.5 


1.4569 


56.5 


1.4636 


66.5 


1.4700 


76.5 


1.4762 


47.0 


1.4572 


57.0 


1.4639 


67.0 


1.4704 


77.0 


1.4765 


47.5 


1.4576 


57.5 


1.4642 


67.5 


1.4707 


77.5 


1.4768 


48.0 


1.4579 


58.0 


1.4646 


68.0 


1.4710 


78.0 


1.4771 


48.5 


1.4583 


68.5 


1.4649 


68.5 


1.4713 


78.5 


1.4774 


49.0 


1.4586 


59.0 


1.4652 


69.0 


1.4717 


79.0 


1.4777 


49.5 


1.4590 


59.5 


1.4656 


69.5 


1.4720 


79.5 


1.4780 



MELTING POINT OF FATS AND FATTY ACIDS. 

Wiley Method. — Official. 

9 REAGENT. 

Alcohol-water mixture. — Specific gravity same as that of the fat to be examined. 
Prepare by boiling, separately, water and 95% alcohol by volume for 10 minutes 
to remove the gases which may be held in solution. While still hot pour the water 
into the test tube until it is almost half full. Nearly fill the test tube with the hot 
alcohol, poured down the side of the inclined tube to avoid too much mixing. If 
the alcohol be added after the water has cooled, the mixture will contain so many 
air bubbles as to be unfit for use. 



1 DETERMINATION. 

Prepare disks of fat as follows: Allow the melted and filtered fat to fall a distance 
of 15-20 cm. from a dropping tube upon a piece of ice or upon the surface of cold 
mercury. The disks thus formed should be 1-1.5 cm. in diameter and weigh about 



302 METHODS OF ANALYSIS [Chap. 

200 mg. When solid remove the disk and allow to stand 2-3 hours in order to obtain 
the normal melting point. 

Place a test tube, 30 by 3.5 cm., containing the alcohol-water mixture, in a tall 
beaker, 35 by 10 cm., containing ice and water, until cold. Then drop the disk of 
fat into the tube and it will at once sink to a point where the density of the alcohol- 
water mixture is exactly equivalent to its own. Lower an accurate thermometer, 
which can be read to 0.1°C., into the test tube until the bulb is just above the disk. 
In order to secure an even temperature in all parts of the alcohol-water mixture 
around the disk, stir gently with the thermometer. Slowly heat the water in the 
beaker, constantly stirring it by means of an air blast or other suitable device. 

When the temperature of the alcohol-water mixture rises to about 6°C. below 
the melting point of the fat, the disk of fat begins to shrivel and gradually rolls up 
into an irregular mass. Lower the thermometer until the fat particle is even with 
the center of the bulb. Rotate the thermometer bulb gently and regulate the 
temperature so that about 10 minutes for the increment of the last 2°C. are 
required. As soon as the fat mass becomes spherical, read the thermometer. 
Remove the tube from the bath and again cool. Place in the bath a second tube 
containing the alcohol-water mixture. The test tube is of sufficiently low tempera- 
ture to cool the bath to the desired point, ice water having been used for cooling. 
After the first or preliminary determination, regulate the temperature of the bath 
so as to reach a maximum of about 1.5°C. above the melting point of the fat under 
examination. 

Do not allow the edge of the disk to touch the sides of the tube. If so, make a 
new determination. Run triplicate determinations of which the second and third 
results should agree closely. 

11 Capillary Tube Method^. — Tentative. 

Draw the melted fat or fatty acids into a thin-walled capillary tube. Use a 
column of fat 1-2 cm. long, according to the length of the thermometer bulb. Seal 
1 end of the tube and cool on ice 12-15 hours. Attach the capillary tube to the bulb 
of an accurate thermometer, graduated to 0.2°C., immerse in a large test tube of 
water surrounded by a beaker of water and heat very slowly. An apparatus 
similar to that indicated in Fig. 12 may be used. The temperature at which the 
substance becomes transparent is taken as the melting point. 

TITER TEST, 
Alcoholic or Aqueous Sodium Hydroxid Method. — Tentative. 

1 2 APPARATUS. 

Standard thermometer. — The thermometer must have a zero mark, 0.1° gradua- 
tions between 10°-60°C., and auxiliary reservoirs at the upper end and between the 
0° and the 10° marks. The cavity in the capillary tube between the 0° and the 
10° marks must be at least 1 cm. below the 10° mark, which must be about 3-4 cm. 
above the bulb, the total length of the thermometer being about 38 cm. The bulb 
should be about 3 cm. long and 6 mm. in diameter. The stem of the thermometer 
should be 6 mm. in diameter and made of the best thermometer tubing, with scale 
etched on the stem, the graduation to be clear cut and distinct. The thermometer 
should have been annealed for 75 hours at 450°C., and the bulb should be of Jena 
normal 16'" glass, moderately thin, so that the thermometer will be quick-acting. 



XXIII 1 



FATS AND OILS 



303 



1 3 DETERMINATION. 

Saponify 75 grams of the sample in a metal dish with 60 cc. of 30% sodium hy- 
droxid solution (36° Baum6) and 75 cc. of 95% alcohol by volume or 120 cc. of 
water. Evaporate to dryness over a very low flame or on an iron or asbestos plate, 
stirring constantly. Dissolve the dry soap in a liter of boiling water and, if alcohol 
has been used, boil for 40 minutes to remove it, adding sufficient water to replace 
that lost in boiling. Liberate the fatty acids by adding 100 cc. of 30% sulphuric 




FIG. 12. APPARATUS FOR THE MELTING POINT DETERMINATION. 

acid (25° Baume) and boil until they form a clear, transparent layer. Wash with 
boiling water until free from sulphuric acid, collect in a small beaker and 
place on a steam bath until the water has settled and the fatty acids are clear; then 
decant into a dry beaker, filter while hot and dry 20 minutes at 100°C. When 
dried, cool the fatty acids to 15°-20°C. above the expected titer and transfer to the 
titer tube, 25 by 100 mm. (1 by 4 inches) and made of glass about 1 mm. in thickness. 
Place in a 16 ounce wide-mouthed bottle of clear glass, 70 by 150 mm. (2.8 by 6 



304 METHODS OF ANALYSIS [Chap. 

inches), fitted with a perforated cork, so as to hold the tube rigidly when in position. 
Suspend the standard thermometer so that it can be used as a stirrer, and stir the 
mass slowly until the mercury remains stationary for 30 seconds. Then allow the 
thermometer to hang quietly, with the bulb in the center of the mass, and observe 
the rise of the mercury column. The highest point to which it rises is regarded 
as the titer of the fatty acids. 

Test the fatty acids for complete saponification as follows: 

Place 3 cc. in a test tube and add 15 cc. of 95% alcohol by volume. Bring the 
mixture to a boil and add an equal volume of ammonium hydroxid (sp. gr. 0.96). 
A clear solution should result. The titer must be made at about 20°C. for all fats 
having a titer above 30°C., and at 10°C. below the titer for all other fats. 

14 Glycerol-Potassium Hydroxid Method. — Tentative. 

Heat 75 cc. of glycerol-potassium hydroxid solution (25 grams of potassium hy- 
droxid in 100 cc. of high-test glycerol) to 150°C. in an 800 cc. beaker; then add 50 cc, 
of the oil or melted fat, previously filtered if necessary to remove foreign substances. 
Saponification often takes place almost immediately, but heating, with frequent 
stirring, should be continued for 15 minutes, avoiding a temperature much above 
150°C. When the saponification is complete, as indicated by the perfectly homo- 
geneous solution, pour the soap into an 800 cc. casserole containing about 500 cc. 
of nearly boiling water, add carefully 50 cc. of 30% sulphuric acid and heat the 
solution, with frequent stirring, until the layer of fatty acids separates out perfectly 
clear. Transfer the fatty acids to a tall separatory funnel, wash 3-4 times with 
boiling water to remove all mineral acids, draw the fatty acids off into a small 
beaker, and allow to stand on a steam bath until the water has settled out and the 
acids are clear. Filter into a dry beaker and heat to 150°C. on a thin asbestos plate, 
stirring continually with the thermometer, transfer to a titer tube, fill it to within 
2.5 cm. of the top and take the titer as directed in 1 3. 

lODIN ABSORPTION NUMBER. 

Hubl Method.— Official. 

1 5 REAGENTS. 

(a) Hiibl's iodin solution. — Dissolve 26 grams of pure iodin in 500 cc. of 95% alco- 
hol by volume. Dissolve 30 grams of mercuric chlorid in 500 cc. of 95% alcohol 
by volume. Filter the latter solution, if necessary, and mix the 2 solutions. Let 
the mixed solution stand 12 hours before using. The solution loses strength with 
age, but can be used so long as 35 cc. of N/10 thiosulphate are equivalent to 25 cc. 
of the iodin solution. 

(b) N/10 sodium thiosulphate. — Standardize this solution as follows: Place in a 
glass-stoppered flask 20 cc. of the N/10 potassium dichromate and 10 cc. of the 15% 
potassium iodid solution. Add 5 cc. of strong hydrochloric acid. Dilute with 100 
cc. of water and allow the N/10 sodium thiosulphate to flow slowlj' into the flask 
until the yellow color of the liquid has almost disappeared, add a few drops of the 
starch indicator and, with constant shaking, continue to add the N/10 sodium thio- 
sulphate until the blue color just disappears. 

(C) Starch indicator. — Prepare as directed under VII, 3 (a). 

(d) 15% potassium iodid solution. 

(e) N/10 potassium dichromate. — The dichromate solution should be checked 
against pure iron. 



XXIII] FATS AND OILS 305 

16 DETERMINATION. 

Weigh about 0.500 gram of fat, or 0.250 gram of oil (0.100-0.200 gram in the case 
of drying oils which have a very high absorbent power), into a 500 cc. glass-stoppered 
flask or bottle. Dissolve the fat or oil in 10 cc. of chloroform. Add 30 cc. of the 
Htibl iodin solution in the case of fats, or 40-50 cc. in the case of oils. Place the 
bottle in a dark place and allow to stand for 3 hours, shaking occasionally. 

This time must be adhered to closely in order to obtain good results. The time 
allowed does not give the complete iodin absorption power of an oil or fat and can 
not be compared with determinations in which 6-12 hours have been used. It gives 
very satisfactory comparative results, but the time factor must be closely observed. 

The excess of iodin should be at least as much as is absorbed. Add 20 cc. of the 
15% potassium iodid solution, shake thoroughly and then add 100 cc. of water, wash- 
ing down any free iodin that may be found on the stopper. Titrate the iodin with 
the N/10 sodium thiosulphate, adding the latter gradually, with constant shaking, 
until the yellow color of the solution has almost disappeared. Add a few drops of 
the starch indicator and continue the titration until the blue color has entirely 
disappeared. Toward the end of the titration, stopper the bottle and shake vio- 
lently, so that any iodin remaining in solution in the chloroform may be taken up 
by the potassium iodid solution. Conduct 2 blank determinations along with that 
on the sample. The number of cc. of the N/10 sodium thiosulphate required by the 
blank less the amount used in the determination gives the thiosulphate equivalent 
of the iodin absorbed by the fat or oil. Ascertain the iodin nmnber by calculating 
the per cent by weight of iodin absorbed. 

Hanus Method. — Official. 

17 REAGENTS. 

Hanus' iodin solution. — Dissolve 13.2 grams of iodin in 1 liter of glacial acetic 
acid (99.5%) which shows no reduction with dichromate and sulphuric acid. Add 
enough bromin to double the halogen content as determined by titration (3 cc. of 
bromin are about the proper amount). The iodin may be dissolved by heating 
but the solution should be cold when the bromin is added. 

A convenient way to prepare the Hanus solution is as follows: Measure 825 cc. 
of acetic acid which has shown no reduction by the dichromate test and dissolve in 
it 13.615 grams of iodin with the aid of heat. Cool and titrate 25 cc. of this solu- 
tion against the N/10 sodium thiosulphate. Add 3 cc. of bromin to 200 cc. of acetic 
acid and titrate 5 cc. of the solution against the N/10 sodium thiosulphate. Cal- 
culate the quantity of bromin solution required exactly to double the halogen con- 
tent of the remaining 800 cc. of iodin solution as follows: 

A = ^ in which 

A = cc. of bromin solution required; 

B = 800 X the thiosulphate equivalent of 1 cc. of iodin sdution; 

C = the thiosulphate equivalent of 1 cc. of bromin solution. 
Example: 136.15 grams of iodin are dissolved in 8250 cc. of acetic acid. 30 cc. 
of bromin are dissolved in 2000 cc. of acetic acid. Titrating 50 cc. of the lodm 
solution against the standard thiosulphate shows that 1 cc. of the lodm solution 
equals 1.1 cc. of the thiosulphate (0.0165 gram of iodinj . Titrating 5 cc. of the bro- 
min solution shows that 1 cc. of the bromin solution equals 4.6 cc. of the thiosulphate. 
Then the quantity of bromin solution required to double the halogen content of 

8200 X 1 1 
the remaining 8200 cc. of iodin solution is equivalent to ^ g— ^ or 1961 cc. Upon 



306 METHODS OF ANALYSIS [Chap. 

mixing the 2 solutions in this proportion, a total volume of 10161 cc. is obtained, 
containing 135.3 grams of iodin. In order to reduce this solution to the proper 
strength (13.2 grams iodin per liter), 10.161 X 13.2 = 1.34.1; 135.3 - 134.1 = 1.2 grams 

of iodin present in excess, or ' — = 91 cc. of acetic acid which must be added. 



The other reagents used are described under 15. 



18 



DETERMINATION. 



Weigh about 0.500 gram of fat. or 0.250 gram of oil (0.100-0.200 gram in the case 
of drying oils which have a very high absorbent power), into a 500 cc. glass-stoppered 
flask or bottle. Dissolve the fat, or oil, in 10 cc. of chloroform, add 25 cc. of the 
Hanus iodin solution and allow to stand for 30 minutes, shaking occasionally. 
The excess of iodin should be at least 60% of the amount added. Add 10 cc. of the 
15% potassium iodid solution and continue as directed under 16. 

SAPONIFICATION NUMBER (KOETTSTORFER NUMBER).-OFFICIAL. 
1 REAGENTS. 

(a) 'N 1^ hydrochloric acid. — Prepare as directed under I, 16 (a). 

(b) Alcoholic potassium hydroxid solution. — Dissolve 40 grams of the purest 
potassium hydroxid in 1 liter of 95% redistilled alcohol by volume. The alcohol 
should be redistilled from potassium hydroxid over which it has been standing for 
some time, or with which it has been boiled for some time using a reflux condenser. 
The solution must be clear and the potassium hydroxid free from carbonates. 

20 DETERMINATION. 

Weigh accurately about 5 grams of the filtered sample into a 250-300 cc. Erlen- 
meyer flask. Pipette 50 cc. of the alcoholic potassium hydroxid solution into the 
flask, allowing the pipette to drain for a definite time. Connect the flask with an 
air condenser and boil until the fat is completely saponified (about 30 minutes). 
Cool and titrate with the N/2 hydrochloric acid, using phcnolphthalein as an indi- 
cator. Calculate the Koettstorfer number (mg. of potassium hydroxid required to 
saponify 1 gram of fat). Conduct 2 or 3 blank determinations, using the same 
pipette and draining for the same length of time as above. 

21 SOLUBLE ACIDS.— OFFICLM:. 

Place the flask, used in 20, on a water bath ahd evaporate the alcohol. Add such 
an amount of N/2 hydrochloric acid that its volume plus the amount used in titrat- 
ing for the saponification number will be 1 cc. in excess of the amount required to 
neutralize the 50 cc. of the alcoholic potassium hydroxid solution added, and place 
on the steam bath until the separated fatty acids form a clear layer on the upper 
surface of the liquid. Fill to the neck with hot water and cool in ice water until 
the cake of fatty acids is thoroughly hardened. Pour the liquid contents of the 
flask through a filter into a liter flask. P'ill the flask again with hot water, set on 
the steam bath until the fatty acids collect at the surface, cool by immersing in ice 
water, and again filter the liquid into the liter flask. Repeat this treatment with 
hot water 3 times, cooling and collecting the washings in the liter flask after each 
treatment. Titrate the combined washings with N/10 alkali, using phcnolphthalein 
as an indicator. Subtract 5 (corresponding to the excess of 1 cc. of N/2 acid) from 
the number of cc. of N/10 alkali used and multiply by 0.0088 to obtain the weight 
of soluble acids as butyric acid. Calculate the percentage of soluble acids. 



XXIII] FATS AND OILS 307 

22 INSOLUBLE ACIDS (HEHNER NUMBER).— OFFICIAL. 

Allow the flask, containing the cake of insoluble fatty acids from 21 and the 
paper through which the soluble fatty acids have been filtered, to drain and dry. 
for 12 hours. Transfer the cake, together with as much of the fatty acids as can 
be removed from the filter paper, to a weighed, wide-mouthed beaker flask. Then 
place the funnel, containing the filter, in the neck of the flask and wash the paper 
thoroughly with hot absolute alcohol. Remove the funnel, evaporate off the alco- 
hol, dry for 2 hours at 100°C., cool in a desiccator and weigh. Again dry for 2 hours, 
cool and weigh. If there is any considerable decrease in weight, re-heat for 2 hours 
and weigh again. Calculate the percentage of insoluble fatty acids. 

SOLUBLE VOLATILE ACIDS (REICHERT-MEISSL NUMBER). 

(As these determinations are entirely empirical, the directions given must b^ , 
followed exactly. In reporting results the method used should always be stated.) 

Reichert-Meissl Method.^OJficial. 

23 REAGENTS. 

(a) Sodium hydroxid solution {1 to 1). — The sodium hydroxid should be as free aa 
possible from carbonates. Protect the solution from contact with carbon dioxid. 
Allow to settle and use only the clear liquid. 

(b) Potassium hydroxid solution. — Dissolve 100 grams of the i)urest potassium 
hydroxid in 58 cc. of hot water. Cool in a stoppered vessel, decant the clear solu- 
tion and protect from contact with carbon dioxid. 

(C) 95% alcohol by volume. — Distilled over sodium hydroxid. 

(d) Dilute sulphuric acid. — Dilute 200 cc. of the strongest acid to 1 liter with 
water. 

(e) Barium {or sodiiim) hydroxid solution. — Standardize an a]3proximately N/10 
solution. 

(f ) Indicator. — Dissolve 1 gram of phenolphthalein in 100 cc. of 95% alcohol. 

(^) Pumice stone. — Heat small pieces to a white heat, plunge in water, and keep 
under water until used. 



24 



SAPONIFICATION. 



Weigh 5.75 cc, about 5 grams, of the filtered sample, into a saponification flask 
and proceed by 1 of the following 3 methods. 

(1) Under pressure with alcohol. — Place 10 cc. of the 95% alcohol in the flask 
containing the fat (the flask must be made of strong, well-annealcd glass, capable 
of resisting the tension of alcoholic vapor at 100°C.) and add 2 cc. of the sodium 
hydroxid solution. Insert a soft, cork stopper into the neck of the flask, tie down 
and place the stoppered flask on a water or steam bath for at least an hour, 
rotating the flask gently from time to time. Cool before opening. 

(2) Under pressure without the use of alcohol. — Place 2 cc. of the potassium hy- 
droxid solution in the flask containing the fat (the flask being round-bottomed and 
made of well-annealed glass to resist pressure), cork and heat as directed under 
(1). This method avoids the formation of esters and the removal of the alcohol 
after saponification. 

(3) With a reflux condenser and the use of alcohol. — Place 10 cc. of the 95% alcohol 
in the flask containing the fat, add 2 cc. of the sodium hydroxid solution and heat on 
a steam bath until the saponification is complete, using a reflux condenser. 

After the saponification, if alcohol was used, remove it by evaporation on a 
steam bath. 



308 METHODS OF ANALYSIS [Chap. 

25 DISTILLATION AND TITRATION. 

Dissolve the soap, obtained as directed under 24, by adding 135 cc. of recently 
boiled water (132 cc. if potassium hydroxid was used in the saponification) and warm 
on the water bath, with occasional shaking, until the solution is clear. Cool to 
60°-70°C., add 5 cc. of the dilute sulphuric acid (8 cc. if potassium hydroxid was 
used in the saponification), stopper loosely and heat on the water bath until the 
fatty acids form a clear, transparent layer. Cool to room temperature, add a few 
pieces of the pumice stone and connect with a glass condenser by means of a bulb 
tube. Heat slowly with a free flame until ebullition begins and distil, regulating 
the flame so as to collect 110 cc. of distillate in as nearly 30 minutes as possible. 
Mix this distillate, filter through a dry filter, and titrate 100 cc. with the standard 
barium or sodium hydroxid solution, using phenolphthalein as an indicator. The 
red color should remain unchanged for 2-3 minutes. 

Multiply the number of cc. of N/10 alkali used by 1.1, divide by the weight 
of fat taken and multiply by 5 to obtain the Reichert-Meissl number. Correct the 
result by the figure obtained in a blank determination. 

Leffman and Beam Method. — Official. 

26 REAGENTS. 

Glycerol-soda solution. — Add 20 cc. of the sodium hydroxid solution, prepared as 
directed under 23 (a), to 180 cc. of pure, concentrated glycerol. 
The other reagents used are described under 23. 

27 DETERMINATION. 

Add 20 cc. of the glycerol-soda solution to about 5 grams of the fat in a flask, 
weighed as directed under 24, and heat over a free flame, or on an asbestos plate, 
until complete saponification takes place, as shown by the mixture becoming 
perfectly clear. If foaming occurs, shake the flask gently. 

Add 135 cc. of recently boiled water, drop by drop at first, to prevent foaming, 
and 5 cc. of the dilute sulphuric acid, distil without previous melting of the fatty 
acids, using an apparatus similar to that illustrated in 28, Fig. 13, regulating the 
flame so as to collect 110 cc. of distillate in as nearly 30 minutes as possible. Filter, 
titrate the volatile acids and calculate the Reichert-Meissl number, as directed 
under 25. Conduct a blank determination and correct the result accordingly. 

INSOLUBLE VOLATILE ACIDS (POLENSKE NUMBER). 

28 Polenske Method^. — Tentative. 

Proceed as directed under 27 up to the point at which 110 cc. of distillate have 
been collected, except that only 20 minutes are allowed for the distillation, em- 
ploying an apparatus of the exact dimensions illustrated in Fig. 13. Substitute a 
25 cc. cylinder for the receiving flask to collect any drops that may fall after the 
flame has been removed. Immerse the flask containing the distillate almost com- 
pletely in water at 15°C. for 15 minutes, filter the 110 cc. of distillate and determine 
the approximate Reichert-Meissl number, if desired, as in 27, avoiding too violent 
shaking of the distillate and consequent emulsification of the insoluble acids pre- 
vious to filtration. Remove the remainder of the soluble acids from the insoluble 
acids upon the filter paper by washing with 3 successive portions of 15 cc. of water, 
previously passed through the condenser, the 25 cc. cylinder and the 110 cc. receiv- 
ing flask. Then dissolve the insoluble acids by passing 3 successive 15 cc. por- 



xxin] 



FATS AND OILS 



309 



tions of neutral 90% alcohol by volume through the filter, each portion previously 
passed through the condenser, the 25 cc. cylinder and the 110 cc. receiving flask. 
Titrate the combined alcoholic washings with N/10 sodium hydroxid, using phenol- 
phthalein as an indicator. 

Run a blank in the same manner and subtract the quantity of the standard alkali 
required to neutralize the 45 cc. of alcohol, used in washing the apparatus and filter 
paper of the blank, from that required in each Polenske determination. Report 
the Polenske number as the number of cc. of N/10 alkali required to neutralize the 
insoluble volatile acids from the 110 cc. of distillate as obtained above. Since the 
entire distillate is filtered it is not necessaiy to multiply the burette reading by 1.1, 
as in 25, but a calculation must be made, as directed in 25, to reduce the actual 
number of cc. found in the titration to the number which would have been required 
had exactly 5 grams of fat been used. 




FIG. 13. APPARATUS^ FOR THE DETERMINATION OF THE POLENSKE NUMBER. 
LIQUID AND SOLID FATTY ACIDS. 
29 Muter Method, Modified by Lane^. — Tentative. 

Weigh 5 grams of the oil or fat into an Erlenmeyer flask, saponify, precipitate with 
lead acetate solution and treat the precipitated lead soap with ether, as directed 
under 37. Filter the ether solution of the soluble lead soap into a Muter tube or 
separatory funnel and decompose the soap by shaking with 40 cc. of hydrochloric 
acid (1 to 5). The soap is completely decomposed when the ether becomes clear 
and colorless. 

Draw off the lead chlorid from the ether solution and wash the ether free from 
acid. Evaporate, until free from ether, an aliquot of this solution in an atmosphere 
of carbon dioxid, in order to prevent the oxidation of the oleic acid, and weigh to 
determine the per cent of liquid acids; determine the iodin number as directed in 
16 or 18, using 0.2-0.3 gram of this residue. 



310 METHODS OF ANALYSIS [Chap. 

As it is very diflficult to dry the unsaturated acids without very serious oxidation, 
it is just as satisfactory to determine the weight of insoluble acids by the following 
method: 

Wash the insoluble soap left on the filter into a flask, decompose with hydro- 
chloric acid and heat until the fatty acids are melted. Fill the flask with hot water, 
cool, pour off the water and again wash the solidified fatty acids. Dissolve in hot 
95% alcohol by volume, transfer to a weighed dish, remove the alcohol by evapo- 
ration, dry, weigh and calculate the percent of solid fatty acids. 

30 FREE FATTY ACIDS.— OFFICIAL. 

Weigh 20 grams of fat, or oil, into a flask, add 50 cc. of 95% alcohol by volume 
which has been neutralized with dilute sodium hydroxid solution, using phenol- 
phthalein as an indicator, and heat to boiling. Shake the flask thoroughly in order 
to dissolve the free fatty acids as completely as possible. Titrate with N/10 alkali, 
shaking thoroughly until the pink color persists after vigorous shaking. 

Express the results either as percentage of oleic acid, as acid degree (cc. of N/1 
alkali required to neutralize the free acids in 100 grams of oil or fat), or as acid 
value (mg. of potassium hydroxid required to saturate the free acids in 1 gram of fat 
or oil). 

One cc. of N/10 alkali is equivalent to 0.0282 gram of oleic acid. 

ACETYL VALUE. 

31 Benedikt-Lewkowiisch Method^. — Tentative. 

Boil the oil or fat with an equal volume of acetic anhydrid for 2 hours, pour the 
mixture into a large beaker containing 500 cc. of water and boil for 30 minutes. 
To prevent bumping, pass a slow current of carbon dioxid into the liquid through a 
finely drawn out tube reaching nearly to the bottom. Allow the mixture to sepa- 
rate into 2 layers, siphon off the water, and boil the oily layer with fresh water 
until it is no longer acid to litmus paper. Separate the acetylated fat from the water 
and dry and filter in a drying oven. 

Weigh 2-4 grams of the acetylated fats into a flask and saponify with alcoholic 
potash as in 20. If the distillation process is to be adopted, it is not necessary to 
work with a standardized alcoholic potassium hj'droxid solution, but in the fil- 
tration method, which is much shorter, the alcoholic potassium hydroxid solution 
must be measured exactly. In either case evaporate the alcohol after saponification 
and dissolve the soap in water. Then either distil or filter as follows: 

(1) Distillation.— Acidiiy with sulphuric acid (1 to 10) and distil as in 25. As 
several hundred cc. must be distilled, either run a current of steam through or add 
portions of water from time to time (500-700 cc. of distillate will be sufficient). 
Filter the distillates to remove any insoluble acids carried over by the steam and 
titrate with N/10 potassium hydroxid, using phenolphthalein as an indicator. Mul- 
tiply the number of cc. of alkali employed by 5.61 and divide by the weight of sub- 
stance used to obtain the acetyl value. 

(2) Filtration. — Add to the soap solution a quantity of standard sulphuric acid 
exactly corresponding to the amount of alcoholic potassium hydroxid solution 
added, warm gently, filter off the free fatty acids which collect on top, wash with 
boiling water until the washings are no longer acid and titrate the filtrate with N/10 
potassium hydroxid, using phenolphthalein as an indicator. Calculate the acetyl 
value as directed under (1). 



XXIII] FATS AND OILS 311 

CHOLESTEROL AND PHYTOSTEROL IN MIXTURES OF ANIMAL AND VEGETABLE FATS. 

32 Alcohol Extraction Method^°. — Tentative. 

Introduce 200-300 grams of the melted fat into a fiat-bottomed liter flask. Close 
the neck of the flask with a 3-holed stopper and insert through these holes: (1) a 
reflux condenser; (2) a right-angled glass tube, one arm of which reaches to a point 
6 mm. above the surface of the melted fat, the other being closed a short distance 
from the flask by means of a short piece of rubber tubing and a pinch-cock; (3) a 
glass tube bent so that one arm reaches down to the bottom of the flask and the 
other serves as a delivery tube for a 700 cc. round-bottomed flask containing 500 cc. 
of 95% alcohol by volume. 

Place the flasks, containing the melted fat and the alcohol, on a steam bath and 
heat so that the alcohol vapor passes through the melted fat in the liter flask and 
is condensed in the reflux condenser, finally collecting in a layer over the melted 
fat. After all the alcohol has passed in this manner into the flask containing the 
fat, disconnect the flask from which the alcohol has been distilled and attach a 
tube to the short piece of rubber tubing attached to the right-angled glass tube 
[see (2) above] and siphon the alcohol layer back into the alcohol distillation flask. 
Reconnect as at first and again distil the alcohol as in the first operation. When 
all the alcohol has been distilled, siphon it again into the distillation flask and 
extract in the same manner for a third time. 

Discard the fat and retain the alcohol which now contains practically all of the 
cholesterol and phytosterol originally present in the fat. Concentrate the alcoholic 
solution to about 250 cc. and add 20 cc. of potassium hydroxid solution (1 to 1) 
to the boiling liquid. Boil for 10 minutee to insure complete saponification of the 
fat, cool to room temperature and pour into a large separatory funnel containing 
500 cc. of warm ether. Shake to insure thorough mixing and add 500 cc. of water. 
Rotate the funnel gently to avoid the formation of extremely stubborn emulsions, 
but mix the water thoroughly with the alcohol-ether-soap solution. A clear, sharp 
separation takes place at once. Draw off the soap solution and wash the ether layer 
with 300 cc. of water, avoiding shaking. Repeat the washing of the ether solution 
with small quantities of water until all the soap is removed. Transfer the ether 
layer to a flask and distil the ether until the volume of liquid remaining in the 
flask measures about 25 cc. Transfer this residue to a tall 50 cc. beaker and 
continue the evaporation until all the ether is driven off and the residue is per- 
fectly dry. If desired, a tared beaker may be used and the weight of the unsaponi- 
fiable matter determined at this point. 

Add 3-5 cc. of acetic anhydrid to the residue in the beaker, cover the beaker 
with a watch glass and heat to boiling over a free flame. After boiling for a few 
seconds, remove the beaker from the flame, cool and add 35 cc. of 60% alcohol by 
volume. Mix the contents of the beaker thoroughly, filter off the alcoholic solution 
and wash the precipitate with 60% alcohol. Dissolve the precipitate on the filter 
with a stream of hot 80% alcohol by volume and wash the insoluble portion well 
with 80% alcohol. Acetates of cholesterol and phytosterol are dissolved while the 
greater portion of the impurities present (including paraffin and paraffin oil if pres- 
ent) remain behind on the filter. Cool the combined filtrate and washings to a 
temperature of 10°-12°C. and allow to stand at that temperature for 2-3 hours. 
During this time the acetates of cholesterol and phytosterol crystallize from the 
solution. Collect the crystals upon a filter, wash with cold 80% alcohol and then 
dissolve them in a minimum amount of hot absolute alcohol. Collect the alcoholic 
solution of the acetates in a small, glass evaporating dish, add 2 or 3 drops of water 
to the solution and heat if not perfectly clear. Allow the alcohol to evaporate 



312 METHODS OF ANALYSIS [Chap. 

spontaneously, the contents of the dish being stirred occasionally to mix the deposit 
of crystals, which form upon the edges, with the main body of the liquid. As soon 
as a good deposit of crystals has formed, collect them upon a hardened filter, wash 
twice with cold 90% alcohol and dry by suction, drying finally at 100°C. for 30 min- 
utes, and determine the melting point in the apparatus shown in 11, Fig. 12, using 
sulphuric acid in the outer beaker and glycerin in the inner tube. 

The melting point of the first crop of crystals usually gives definite information 
as to the presence or absence of phytosterol but the conclusion indicated should be 
confirmed by recrystallizing the crystals from absolute alcohol and again determin- 
ing the melting point. If the crystals are pure cholesteryl acetate, the melting point 
of the second crop should agree closely with that of the first. If phytosteryl acetate 
is present, however, a higher melting point will be noted, as phytosteryl acetate is 
less soluble in alcohol than cholesteryl acetate. The melting point of cholesteryl 
acetate is 114°C., that of phytosteryl acetate 125°-137°C. 

33 Digitonin Method. {Marcusson and Schilling^'^) — Tentative. 

Shake vigorously 50 grams of the oil or fat for 15 minutes in a separatory funnel 
with 20 cc. of a 1% solution of digitonin in 95% alcohol by volume. Allow the 
mixture to stand for a time until the emulsion separates. The lower or fat layer 
should be quite clear while the alcohol layer contains a bulky, flocculent precipitate. 
Draw off as much as possible of the fat, avoiding any loss of the precipitate. Add 
100 cc. of ether to the alcohol layer and filter the mixture. Wash the precipitate 
with ether until free from fat; after drying in the air, transfer it to a tall 50 cc. 
beaker, add 2-3 cc. of acetic anhydrid and cover the beaker with a watch glass. 
Then boil slowly over a low flame for 30 minutes. After cooling, add 30-35 cc. of 
60% alcohol by volume and mix the contents of the beaker thoroughly. Filter 
off the alcohol solution and wash the precipitate with 60% alcohol, then dissolve it 
on the filter with a stream of hot 80% alcohol by volume from a wash bottle and 
set aside the filtrate in a cool place (10°C. or below). After the acetates have 
crystallized out of this solution filter them off, recrystallize from absolute alcohol, 
dry and determine the melting point of each crop of crystals, as directed under 32. 

34 UNSAPONIFIABLE RESIDUEi^.— TENTATIVE. 

Saponify 5 grams of the oil or fat with alcoholic potassium hydroxid solution and 
remove the alcohol by evaporation. Wash into a separatory funnel with 70-100 cc. 
of water and extract with 50-60 cc. of ether. If the 2 liquids do not separate, add a 
few cc. of alcohol. Separate the water solution and wash the ether with water con- 
taining a few drops of sodium hydroxid solution. Again extract the soap solution 
and washings with ether and evaporate the combined extracts to dryness. In most 
cases it is advisable to add a little alcoholic potassium hydroxid solution to the 
residue and heat in order to saponify any traces of fats left unsaponified and extract 
again with ether. Transfer to a weighed dish and dry as quickly as possible in a 
water oven. 

Many of the hydrocarbon oils are volatile at 100°C., so that the drying should 
not be carried any further than necessary. With resin oil, paraffin wax and the 
denser mineral oils there is little danger of loss at 100°C. 

On account of the solubility of soap in ether and petroleum ether it is well to 
wash the residue with warm water containing a little phenolphthalein. If the 
reaction is alkaline, soap is present and the residue must be further purified. 



XXIII] FATS AND OILS 313 

RESIN OIL. 

35 Qualitative Test. — Tentative. 

Polarize the pure oil, or a definite dilution with petroleum ether, in a 200 mm. 
tube. Resin oil has a polarization in a 200 mm. tube of from + 30° to + 40° on the 
sugar scale (Schmidt and Haensch) while most oils'' read between + 1° and —1°. 

COTTONSEED OIL. 

36 Halphen TesV*.— Official. 

Mix carbon disulphid, containing about 1% of sulphur in solution, with an equal 
volume of amyl alcohol. Mix equal volumes of this reagent and the oil under ex- 
amination, and heat in a bath of boiling, saturated brine for 1-2 hours. In the 
presence of as little as 1% of cottonseed oil, a characteristic red or orange-red color 
is produced. 

Lard and lard oil from animals fed on cottonseed meal will give a faint reaction; 
their fatty acids also give this reaction. 

The depth of color is proportional, to a certain extent, to the amount of oil pres- 
ent, and by making comparative tests with cottonseed oil some idea as to the 
amount present can be obtained. Different oi's react with different intensities, and 
oils which have been heated from 200°-210°C.i* react with greatly diminished in- 
tensity. Heating 10 minutes at 250°C. renders cottonseed oil incapable of giving 
the reaction'^. 

PEANUT OIL. 

37 Modified Renard Tesl^''. — Tentative. 

Weigh 20 grams of the oil into an Erlenmeyer flask. Saponify with alcoholic 
potash solution, neutralize exactly with dilute acetic acid, using phenolphthalein 
as an indicator, and wash into an 800-1000 cc. flask containing a boiling mixture of 
100 cc. of water and 120 cc. of 20% lead acetate solution. Boil for a minute and 
then cool the precipitated soap by immersing the flask in water, occasionally 
giving it a whirling motion to cause the soap to stick to the sides of the flask. After 
the flask has cooled, decant the water and excess of lead acetate solution and wash 
the lead soap with cold water and 90% alcohol by volume. Add 200 cc. of ether, 
cork and allow to stand for some time until the soap is disintegrated; heat on a 
water bath, using a reflux condenser, and boil for about 5 minutes'*. In the case of 
oils, most of the soap will be dissolved, while in lards, which contain much stearin, 
part of the soap will be left undissolved. Cool the ether solution of soap to 15°- 
17°C. and allow to stand until all the insoluble soaps have separated out (about 12 
hours). 

Filter upon a Biichner funnel and thoroughly wash the insoluble lead soaps 
with ether. Wash the ether-insoluble lead soaps into a separatory funnel by means 
of a jet of ether, alternating at the end of the operation, if a little of the soap sticks 
to the paper, with hydrochloric acid (1 to 3). Add sufficient hydrochloric acid (1 to 3) 
so that the total volume of the latter amounts to about 200 cc. and enough ether to make 
the total volume of it 150-200 cc. and shake vigorously for several minutes. Allow the 
layers to separate, run off the acid layer, and wash the ether once with 100 cc. of dilute 
hydrochloric acid and then with several portions of water until the water washings 
are no longer acid to methyl orange. If a few undecomposed lumps of lead soap re- 
main (indicated by solid particles remaining after the third washing with water), 
break these up by running off almost all the water layer and then a add little concen- 
trated hydrochloric acid, shake and then continue the washing with water as before. 



314 METHODS OF ANALYSIS [Chap. 

Distil the ether from the solution of insoluble fatty acids and dry the latter in the 
flask by adding a little absolute alcohol and evaporating on a steam bath. Dissolve 
the dry fatty acids by warming with 100 cc. of 90% alcohol by volume and cool 
slowly to 15°C., shaking to aid crystallization. Allow to stand at 15°C. for 30 
minutes. In the presence of peanut oil, crystals of arachidic acid will separate from 
the solution. Filter, wash the precipitate twice with 10 cc. of 90% alcohol by 
volume, and then with 70% alcohol by volume, care being taken to maintain the 
arachidic acid and the wash solutions at a definite temperature in order to apply 
the solubility corrections given below. Dissolve the arachidic acid upon the filter 
with boiling absolute alcohol, evaporate to dryness in a weighed dish, dry and 
weigh. Add to the weight 0.0025 gram for each 10 cc. of 90% alcohol used in the 
crystallization and washing, if conducted at 15°C. ; if conducted at 20°C., add 0.0045 
gram for each 10 cc. The melting point of arachidic acid thus obtained is 71°- 
72°C. Twenty times the weight of arachidic acid will give the approximate amount 
of peanut oil present. Arachidic acid has a characteristic appearance and may 
be identified by the microscope. As little as 5-10% of peanut oil can be detected 
by this method. 

SESAME OIL. 

38 Baudoin Test. — Official. 

Dissolve 0.1 gram of finely powdered sugar in 10 cc. of hydrochloric acid (sp. 
gr. 1.20), add 20 cc. of the oil to be tested, shake thoroughly for a minute and allow 
to stand. The aqueous solution separates almost at once and, in the presence of 
even a very small admixture of sesame oil, is colored crimson. Some olive oils 
give a slight pink coloration with this reagent. Comparative tests with known 
samples containing sesame oil will differentiate them. 

39 Villavecchia Test^^. — Official. 

Add 2 grams of furfural to 100 cc. of 95% alcohol by volume and mix thoroughly 
0.1 cc. of this solution, 10 cc. of hydrochloric acid (sp. gr. 1.20), and 10 cc. of the oil 
by shaking them together in a test tube. A crimson color is developed as in the 
Baudoin test, 38, where sugar is used. 

Villavecchia explained this reaction on the basis that furfural is formed by the 
action of levulose and hydrochloric acid and therefore substituted furfural for 
sucrose. As furfural gives a violet tint with hydrochloric acid it is necessary to use 
the very dilute solution specified in the method. 

BEEF FAT IN LARD. 

40 Emery Method^°.— Tentative. 

Weigh 5 grams of the melted fat into a glass-stoppered 25 cc. cylinder about 
150-175 mm. in height. Add warm ether up to the 25 cc. mark, stopper securely 
and shake until the fat is completely dissolved. Allow the cylinder to stand for 
about 18 hours at a temperature of 16°-20°C. during which time some of the solid 
glycerides will crystallize out. Decant the clear solution carefully from the crys- 
tals, wash with three 5 cc. portions of cold ether, avoiding breaking up the deposit 
during the first 2 washings. Agitate the crystals with the third portion of ether 
and transfer to a small filter. Wash on the paper with successive small amounts 
of cold ether until 15-20 cc. have been used, then remove the last traces of ether by 
means of slight suction on the stem of the funnel. Break up any large lumps and 
alloAv the deposit to dry. 



XXIII] FATS AND OILS 315 

When thoroughly dry pulverize the glycerides and take their melting point in a 
closed 1 mm. tube, using an apparatus similar to that indicated in 1 1 , Fig. 12. Heat 
the water in the beaker rapidly to about 55°C. and maintain that temperature 
until the thermometer carrying the melting-point tube registers 50°-55°C., then 
heat again and carry the temperature of the outer bath somewhat rapidly to GT^C. 
when the lamp is removed. The melting point of the crystals is regarded as that 
point when the fused substance becomes perfectly clear and transparent. A dark 
background placed about 4 inches from the apparatus will prove of advantage. 
When the melting point of the glycerides obtained by this method is below 63.4°C. 
the presence of beef fat should be suspected, while a melting point of 63°C., or below, 
can be regarded as positive evidence that the sample is not pure lard. It is advis- 
able to carry out this method with a control sample of pure lard in connection with 
each batch of samples analyzed. 

FISH OIL AND MARINE ANIMAL OILS IN THE PRESENCE OF VEGETABLE OILS AND IN THE 
ABSENCE OF METALLIC SALTS. 

41 Qualitative Test. — Tentative. 

Dissolve in a test tube about 6 grams of the oil in 12 cc. of a mixture of equal 
parts of chloroform and glacial acetic acid. Add bromin, drop by drop, until a 
slight excess is indicated by the color, keeping the solution at about 20°C. Allow 
to stand 15 minutes or more and then place the test tube in boiling water. If vege- 
table oils only are present, the solution will become perfectly clear, while fish oils 
will remain cloudy or contain a precipitate due to the presence of insoluble bromids. 

42 COLORING MATTERS.— TENTATIVE. 
Proceed as directed under XI, 3. 

BIBLIOGRAPHY. 

1 Allen. Commercial Organic Analysis. 4th ed., 1909-14, 2:50. 
" Wiley. Principles and Practice of Agricultural Analysis. 2nd ed., 1906-14, 3: 
414; Conn. Agr. Exp. Sta. Rept., 1900, (II), p. 142. 

3 Ber., 1882, 15: 1031; J. Am. Chem. Soc, 1899, 21: 991. 

* J. Soc. Chem. Ind., 1898, 17: 1021. 

"U. S. Bur. Chem. Bull. 13 (IV), p. 448; Lewkowitsch. Chemical Technology 
and Analysis of Oils, Fats and Waxes. 5th ed., 1913-15, 1:319; Wiley. Principles and 
Practice of Agricultural Analysis. 2nd ed., 1906-14, 3 : 390. 

« Arb. kais. Gesundh., 1903-04, 20: 545. 

"> Lewkowitsch. Chemical Technology and Analvsis of Oils, Fats and Waxes. 
5th ed., 1913-15, 2: 425. 

* Analyst, 1889, 14: 61; J. Am. Chem. Soc, 1893, 15: 110. 

9 J. Soc. 'Chem. Ind., 1897, 16:503; Benedikt. Analyse der Fette und Wachs- 
arten. 5th ed., 1908, p. 143; Allen. Commercial Organic Analysis. 4th ed., 1909-14, 
2: 33. 
* 1° U. S. Bur. Animal Industry Circ. 212. 

" Chem. Ztg., 1913, 37: 1001. 

" Allen. Commercial Organic Analysis. 4th ed., 1909-14, 2: 79. 

" Lewkowitsch. Chemical Technology and Analysis of Oils, Fats and Waxes. 
5th ed., 1913-15, 1:343. 

1* J. pharm. chim., 1897, 6th ser., 6:390; Abs. Analyst, 1897, 22:326; Allen. Com- 
mercial Organic Analysis. 4th ed., 1909-14, 2 : 135; Conn. Agr. Exp. Sta. Rept., 1900 
(11), p. 143. 

"Allen. Commercial Organic Anabasis. 4th ed., 1909-14, 2: 135. 

"Abs. J. Soc. Chem. Ind., 1899, 18: 711. 

" Compt. rend., 1871, 73: 1330; Lewkowitsch. Chemical Technology and Analy- 
sis of Oils, Fats and Waxes. 5th ed., 1913-15, 2: 310. 

18 J. Am. Chem. Soc, 1893, 15: 110. 

19 J. Soc. Chem. Ind., 1893, 12: 67; 1894, 13: 69. 
" U. S. Bur. Animal Industry Circ. 132. 



XXrV. SPICES AND OTHER CONDIMENTS. 

SPICES. 

1 PREPARATION OF SAMPLE.— TENTATIVE. 

Grind the sample so as to pass through a sieve having circular openings 1 mm. in 
diameter and mix thoroughly. Owing to the lack of uniformity of most spices 
and the peculiar tendency to stratify, extreme care is necessary in weighing out a 
portion for analysis. Stir the material with a spoon, having a capacity of approxi- 
mately 2 grams, and dip a spoonful from the interior in order that only a very small 
amount needs to be added to or taken from the portion on the scale pan. In the 
determination of starch in spices by the diastase method, reduce a portion of the 
sample to an impalpable powder by grinding in a mortar. 

2 MOISTURE.— TENTATIVE. 

Dry 2 grams to constant weight at 110°C. From the resulting loss in weight 
subtract the amount of volatile ether extract as determined in 9. 

3 ASH.— OFFICIAL. 
Determine as directed under VIII, 4. 

4 SOLUBLE AND INSOLUBLE ASH.— TENTATIVE, 
Proceed as directed under IX, 17, employing the ash obtained in 3. 

5 ASH INSOLUBLE IN ACID.— TENTATIVE. 

Boil the water-insoluble residue, obtained in 4, or the total ash obtained in 3, 
with 25 cc. of 10% hydrochloric acid (sp. gr. 1.050) for 5 minutes, collect the insol- 
uble matter on a Gooch or an ashless filter, wash with hot water, ignite and weigh. 

6 CALCIUM OXID IN ASH.— OFFICLAL. 

Ignite 2-4 grams of the sample as directed under 3, digest with hot 10% hydro- 
chloric acid, evaporate to dryness, moisten the dry residue with dilute hydro- 
chloric acid and again evaporate to dryness to render the silica insoluble. Moisten 
the residue with 5-10 cc. of hydrochloric acid, add about 50 cc. of water, allow to 
stand on a water bath for a few minutes, filter and wash the insoluble residue with 
hot water. Determine calcium oxid in the combined filtrate and washings as directed 
under XXVIII, 23. 

7 NITROGEN.— OFFICIAL. 

Determine as directed under I, 18, 21 or 23, except in the case of black and 
white peppers in which use only the Kjeldahl-Gunning-Arnold method^ [I, 23], 
employing 1 gram of the sample. 

NITROGEN IN NON-VOLATILE ETHER EXTRACT. 

8 Winton, Ogden and Mitchell Method. — Tentative. 

(For black and white peppers.) 

Extract 10 grams of the pepper for 20 hours in a continuous extraction apparatus 
with absolute ether, collecting the extract in a weighed 250 cc. flask. Evaporate 

317 



318 METHODS OF ANALYSIS [Chap. 

the ether, dry first at 100°C. and finally to constant weight at 110°C. Determine 
the nitrogen in the weighed extract, as directed in I, 23, digesting in the same flask 
used for the extraction. Calculate the parts of nitrogen per 100 parts of non-vola- 
tile ether extract. If desired, crude piperin may be calculated from the nitrogen 
by multiplying by 20.36. 

9 VOLATILE AND NON-VOLATILE ETHER EXTRACT^.— TENTATIVE. 

Extract 2 grams of the ground material for 20 hours in a continuous extrac- 
tion apparatus with anhydrous ether [VIII, 9]. Transfer the ethereal solution to 
a tared capsule and allow to evaporate at room temperature. Let stand for 18 
hours over sulphuric acid and weigh the total ether extract. Heat the extract 
gradually and then to constant weight at 110°C. The loss is volatile ether extract; 
the residue, non-volatile ether extract. 

10 ALCOHOL EXTRACT'.— TENTATIVE. 

Place 2 grams of the sample in a 100 cc. flask and fill to the mark with 95% alcohol 
by volume. Stopper, shake for 8 hours at 30 minute intervals and allow to 
stand for 16 hours longer without shaking. Filter the extract through a dry 
filter, evaporate a 50 cc. aliquot of the filtrate to dryness in a flat-bottomed dish 
on a water bath and heat to constant weight at 110°C. 

11 COLD-WATER EXTRACT.— TENTATIVE. 

(For ginger.) 

Place 4 grams of the sample in a 200 cc. graduated flask, add water to the mark, 
shake at 30 minute intervals du^-ing 8 hours and let stand 16 hours longer with- 
out shaking. Filter and evaporate a 50 cc. aliquot of the filtrate to dryness in a 
flat-bottomed, metal dish. Dry to constant weight at 100°C. 

12 COPPER-REDUCING SUBSTANCES BY DIRECT INVERSION.— TENTATIVE. 

Extract 4 grams of the sample with 5 successive portions of 10 cc. of ether on a 
filter that will retain completely the smallest starch granules. After the ether 
has evaporated, wash with 150 cc. of 10% alcohol by volume. 

Owing to the formation of a glutinous mass which clogs the filter, it is not possible 
to wash samples of Batavia cassia with water or dilute alcohol. Therefore all pre- 
liminary washing is best omitted in determinations made on all varieties of cassia, 
as well as on cassia buds and cinnamon. 

Carefully wash the residue from the paper into a 500 cc. flask with 200 cc. of 
water, using a small wash bottle, and gently rubbing the paper with the tip of the 
finger. Hydrolyze and determine the copper reducing material as directed under 
VIII, 60. Express the result in terms of starch. 

13 STARCH.-TENTATIVE. 

Extract 4 grams of the finely pulverized sample with ether and 10% alcohol by 
volume, as directed under 12, and determine starch by the diastase method, as 
directed under VIII, 62. 

14 CRUDE FIBER.— TENTATIVE. 

Proceed as directed under VIII, 68, and remove all ether extractives by suc- 
cessive washings of the dry fiber with ether previous to weighing. 



XXrV] SPICES AND OTHER CONDIMENTS 319 

15 TANNIN.— TENTATIVE. 

(For cloves and allspice.) 

Extract 2 grams of the sample for 20 hours with anhydrous ether. Boil the 
residue for 2 hours with 300 cc. of water, cool, make up to 500 cc. and filter. Measure 
25 cc. of this infusion into a 1200 cc. flask, add 20 cc. of indigo solution, 750 cc. of 
water and proceed as directed under XVI, 32. One cc. of N/10 oxalic acid is 
equivalent to 0.006232 gram of quercitannic acid, or 0.0008 gram of oxygen absorbed. 

IB TOTAL SULPHUR.— OFFICIAL. 

(For mustard.) 
Proceed as directed under III, 17. 

OLIVE OIL. 

(For paprika.) 
17 Qualitative Test. — Tentative. 

Spread 5 grams of the paprika on a watch glass and dry over sulphuric acid for 
at least 12 hours. Measure 250 cc. of anhydrous, alcohol-free ether [VIII, 9] into a 
graduated flask on which the mark is situated near the lower end of the neck, and 
brush the paprika into it. Place a mark on the neck of the flask at the point where 
the meniscus is, and allow to stand for an hour, shaking at 20 minute intervals 
during that time. Bring the meniscus back to the mark placed upon the neck, either 
by cooling the flask and contents if the level has risen, or by adding absolute ether 
if it has fallen; let the solid particles settle and pipette off 100 cc. of the supernatant 
liquid, filter through an 11 cm. closely woven paper into a tared, air-dry, 250 cc, 
glass-stoppered Erlenmeyer flask that has been counterpoised against a similar 
flask; wash the paper with a little absolute ether. Then distil off the solvent and 
remove the flask from the bath as soon as the ether ceases to come over. Lay the 
flask on its side in a water oven and heat for 30 minutes; cool the open flask for at 
least 30 minutes in the air and weigh. Repeat this heating and weighing until the 
weight is constant to within 1 mg., 2 heatings usually being sufficient. Note the 
per cent of ether extract obtained. If more than 1| hours of heating are required 
to obtain constant weight, or if the ether extract becomes colorless, reject it and 
start a new determination with freshly purified ether. 

Dissolve the ether extract in the flask with 10 cc. of chloroform, add 30 cc. of 
Hanus' solution [XXIII, 17 (a)] and proceed as directed under XXIII, 18, allow- 
ing 30 minutes for the halogen absorption. Note the iodin number of the ether 
extract. The iodin number of pure paprika thus obtained should not be less than 

125. 

MICROSCOPIC EXAMINATION.— TENTATIVE. 

18 GENERAL. 

Adulterants of vegetable origin in spices are detected best by means of the mi- 
croscope. A general knowledge of vegetable histology and the microscopic appear- 
ance of the spices and spice adulterants is essential. Some of the standard works* 
on these subjects are listed in the bibliography. 

19 REAGENTS. 

Of the numerous reagents employed in histological work the following are the 
most useful in spice examinations : — 

(a) Glycerol solution {1 to 1). 

(b) Absolute alcohol. 



320 METHODS OF ANALYSIS [Chap. 

(C) Ether. 

(d) Ammonium hydroxid. — The concentrated solution, containing about 30% of 
ammonia gas, is used in making Schweitzer's reagent and for some other purposes. 
For the turmeric test the concentrated solution should be diluted with 10 parts of 
water. 

(e) 5% potassium hydroxid solution. 

(f) Chloral hydrate solution (8 to 5). 

(g) Schultze's mixture. — Crystallized potassium chlorate mixed with nitric acid 
as needed. 

(h) lodin-potassium iodid solution. — A solution of 0.05 gram of iodin, 0.2 gram 
of potassium iodid in 15 cc. of water. 

(i) Chlor-zinc iodin solution. — Dissolve 100 grams of zinc chlorid in 60 cc. of water 
and to this add 20 grams of potassium iodid and 0.5 gram of iodin crystals. A few 
crystals of iodin should be left in the bottle to insure saturation and allowed to 
stand a few hours before using. The chlor-zinc iodin solution, prepared in this 
manner, will keep for months. If the color developed in the tissue is too deep a blue, 
a very slight dilution of the reagent is advisable. 

(j) Millon's reagent. — Prepare as in XV, 9. 

(k) 1% ferric acetate or chlorid solution. — Freshly prepared. 

(1) Alkanna tincture. — Macerate 20 grams of alkanet root for several days with 
100 cc. of alcohol. 

(m) Aqueous safranin solution. 

(n) 10% hydrochloric acid. 

(O) Acetic acid. — Glacial or 99% acetic acid diluted with 2 parts of water. 



20 



APPARATUS. 



(a) Dissecting microscope or hand lens. 

(b) Compound microscope. — Provided with f and I inch objectives, 1 and 2 inch 
oculars, double nosepiece, eyepiece micrometer and polarizing apparatus. 

(C) Sieves. — A series of sieves with meshes ranging from 0.2-2 mm. 
(d) Slides, cover-glasses, needles, scalpels, forceps, etc. 



21 



PREPARATION OF SAMPLE. 



Reduce one portion to a fine powder in a mortar. Separate another portion into 
several grades of fineness by sieves of different mesh or by jarring on a sheet of 
paper. In the coarser grades, fragments of a suspicious nature may often be seen 
with the naked eye or under a simple microscope; these should be picked out for 
subsequent examination under the compound microscope. 



22 



EXAMINATION. 



Mount a small quantity of the ground sample in water and examine under the 
compound microscope with both ordinary and polarized light. This gives general 
information as to the nature of the material and serves for the detection and iden- 
tification of starch granules and various tissues. Draw a small drop of the iodin- 
potassium iodid solution into the same preparation by means of a piece of filter 
paper placed on the opposite edge of the cover-glass and examine. Starch gran- 
ules will be colored blue or blue-black, cellulose yellow, and proteins either brown 
or yellow. 

In the manner just described draw a little of the 5% potassium hydroxid solution 
under the cover-glass and again examine. This treatment gelatinizes the starch 



XXIV] SPICES AND OTHER CONDIMENTS 321 

granules, dissolves the proteins, saponifies the fats, and in other ways clears the 
preparation. It also imparts to tannins a reddish color. If this treatment does 
not clear the tissues satisfactorily, treat a fresh portion for some hours with the 
chloral hydrate solution. 

Examine also the crude fiber obtained in the chemical analysis, as in this mate- 
rial the stone cells and other tissues are shown distinctly. 

To isolate stone cells, bast fibers and other thick-walled cells macerate a por- 
tion of the sample in Schultze's mixture, using such proportion of potassium chlor- 
ate and nitric acid and heating for such a time as secures the desired results. Pow- 
dered charcoal and charred shells resist the bleaching action of potash, chloral 
hydrate and Schultze's mixture. 

If it is desired to distinguish cellulose from infiltrated substances (lignin, suberin, 
etc.), add the freshly prepared chlor-zinc iodin solution to a water mount, whereby 
the former is colored blue and the latter yellow. 

Test for proteins by cautiously warming on a slide with a drop of freshly pre- 
pared Millon's reagent. The proteins are partially decomposed, acquiring grad- 
ually a brick-red color. If it is desired to study the form of the aleurone (pro- 
tein) granules, which in some plants are quite as characteristic as starch granules, 
prepare a mount in pure glycerol or oil. 

To distinguish fats, oils, essential oils and resins from other cell contents, treat 
for an hour with the alkanna tincture, diluted with an equal bulk of water, which 
imparts to these substances a deep red color, or treat with ether, which dissolves 
them. Treat also with alcohol, which dissolves the essential oils and resins, but 
does not perceptibly affect the fats and oils. 

In testing for tannins and tissues impregnated with these substances, add the 
1% ferric acetate or chlorid solution. Both of these reagents give a green or blue 
color with tannins, but the former acts more slowly and is to be preferred. 

Crystals of calcium oxalate are recognized by their characteristic forms and 
their behavior to polarized light. To distinguish calcium oxalate from calcium 
carbonate, treat with acetic acid, which does not affect the former, but dissolves 
the latter with effervescence. Both are soluble in hydrochloric acid. 

PREPARED MUSTARD. 

23 PREPARATION OF SAMPLE.— TENTATIVE. 

Transfer the entire contents of the container to a dish sufficiently large to stir 
thoroughly and make the whole mass homogeneous. Preserve in a bottle having 
a tightly fitting glass stopper. Stir well each time before removing a portion for 
analysis. 

24 ' SOLIDS.— TENTATIVE. 

Weigh 5 grams of the sample into a flat-bottomed, platinum dish, distribute 
evenly over the bottom of the dish with a little water, place on a water bath until 
the mixture appears dry, and heat finally to constant weight at 100°C. in a water 
oven. 

25 ASH.— OFFICIAL. 

Ignite the dry residue, obtained in the determination of solids, 24, as directed 
under VIII, 4. 

26 SALT.— TENTATIVE. 
Determine chlorin in the ash as directed under III, 15. 



322 METHODS OF ANALYSIS [Chap. 

27 ETHER EXTRACT.— TENTATIVE. 

Weigh 10 grams of the sample into a capsule and mix with about 30 grams of 
sand. Heat on a water bath until the mixture appears dry and complete the dry- 
ing in a water oven. Grind until all the lumps are broken up, and determine the 
ether extract as directed under VIII, 10. 

28 PROTEIN.— OFFICIAL. 

Determine the nitrogen as directed under I, 18, 21 or 23, using 5 grams of the 
sample. Multiply the result by 6.25 to obtain the amount of protein. 

29 ACIDITY.— TENTATIVE. 

Weigh 10 grams of the sample into a 200 cc. graduated flask, make up to the 
mark with water, shake, filter through a dry paper and determine the acidity in 
100 cc. by titration with N/10 alkali, using phenolphthalein as an indicator. Ex- 
press the result as acetic acid. One cc. of N/10 alkali is equivalent to 0.0060 gram 
of acetic acid. 

30 COPPER-REDUCING SUBSTANCES.— TENTATIVE. 

By Direct Inversion. 

Proceed as directed under VIII, 60, except that 10 grams of the sample, without 
previous washing or extraction, are treated directly with 200 cc. of water and 20 cc. 
of 25% hydrochloric acid and the solution is made up to 250 cc. after neutralizing 
and before filtering and drawing off the aliquot. In analyses of samples contain- 
ing starch, particular attention should be given that the amount of dextrose 
present in the aliquot taken for the reducing sugar determination does not exceed 
the maximum permitted for that determination. Calculate the result in terms of 
starch. 

31 CRUDE FIBER.— TENTATIVE. 

Transfer 8 grams of the sample (equivalent to about 2 grams of dry matter) to a 
porcelain or glass mortar. Treat with a little hot 1.25% sulphuric acid and rub into 
a uniform thin paste. It is absolutely essential that this paste be uniform in con- 
sistency and entirely free from lumps. Rinse the thin mixture into a 500 cc. Erlen- 
meyer flask, using a total volume of 200 cc. of the hot 1.25% sulphuric acid for the 
entire operation. Proceed as directed under VIII, 68, and remove all the fat, pre- 
vious to weighing of the crude fiber, by repeated washings of the dry fiber with 
ether. 

32 COLORING MATTERS.-TENTATIVE. 
Proceed as directed under XI. 

33 PRESERVATIVES.— TENTATIVE. 

Proceed as directed under X. 

TOMATO PRODUCTS. 

34 PREPARATION OF SAMPLE.— TENTATIVE. 

Shake the package and contents thoroughly to incorporate any sediment, then 
transfer the entire contents of the container to a large glass or porcelain dish and 
mix thoroughly, continuing the stirring for at least 1 minute. Transfer the well 
mixed sample to a glass-stoppered container and shake or stir thoroughly each time 
before removing portions for analysis. 



XrV] SPICES AND OTHER CONDIMENTS 323 

5 TOTAL SOLIDS— TENTATIVE. 

Weigh 10 grams of the sample into a flat-bottomed, platinum dish having a diam- 
eter of about 6 cm., spread the sample in a thin layer, evaporate to dryness on a 
steam bath and dry in a water oven for 4 hours. 

36 INSOLUBLE SOLIDS.— TENTATIVE. 

Wash 20 grams of the sample repeatedly with hot water, centrifugalizing after 
each addition of water and pouring the clear, supernatant liquid through a tared 
triple filter paper on a Biichner funnel. After 4-5 washings transfer the remaining 
insoluble matter to the filter, dry for 2 hours at 100°C., cool in a desiccator and 
weigh rapidly. The paper used should be dried for 2 hours at 100°C., cooled in a 
desiccator and weighed. A cylinder, 1-1 1 inches in diameter and 5-6 inches long, 
is convenient for washing and centrifugalizing. 

37 SOLUBLE SOLIDS.— TENTATIVE. 

Subtract the percentage of insoluble solids from the percentage of total solids 
to obtain the percentage of soluble solids. 

38 SAND.— TENTATIVE. 

Weigh 100 grams of the well mixed sample into a 2-3 liter beaker, nearly fill the 
beaker with water, and mix the contents thoroughly. Allow to stand 5 minutes 
and decant the supernatant liquid into a second beaker. Refill the first with water 
and again mix the contents. After 5 minutes more decant the second beaker into 
a third, the first into the second, refill and again mix the first. Continue this opera- 
tion, decanting from the third beaker into the sink until the lighter material is 
washed out from the ketchup. Then collect the sand from the 3 beakers on a tared 
Gooch crucible, dry, ignite and weigh. Attention is especially called to the fact 
that under "Sand" only the figure obtained by this method should be reported. 
The results obtained by the determination of ash insoluble in hydrochloric acid 
are not applicable to the determination of sand, since the sand is so unevenly dis- 
tributed that reliable results can only be obtained by taking a larger sample than 
is possible in the determination of ash. 

39 ASH.— OFFICIAL. 

Evaporate 10 grams of the sample to dryness on a water bath and ignite as directed 
under VIII, 4. 

40 ALKALINITY OF THE ASH.— TENTATIVE. 

Proceed as directed under XIII, 7. Express the result as the number of cc. of 
N/10 acid required to neutralize the ash from 100 grams of the sample. 

41 SODIUM CHLORID.— OFFICIAL. 

Proceed as directed under III, 15, using either an aliquot of the solution obtained 
in 40 or a nitric acid solution of the whole ash. 

42 REDUCING SUGARS BEFORE INVERSION.— TENTATIVE. 

Weigh 20 grams of the sample into a 200 cc. flask, dilute with about 100 ce. of 
water, clarify with a slight excess of neutral lead acetate solution, dilute to the 
mark and filter. Remove the excess of lead with anhydrous sodium or potassium 
oxalate. Filter and determine reducing sugars as directed under VIII, 25. Ex- 
press the result as per cent of invert sugar. 



324 METHODS OF ANALYSIS [Chap. 

43 REDUCING SUGARS AFTER INVERSION.— TENTATIVE. 

Transfer 50 cc. of the filtrate, obtained in 42, to a 100 cc. fiask, add 5 cc. of con- 
centrated hydrochloric acid and let stand overnight. Nearly neutralize with 
sodium hydroxid solution, cool, dilute to the mark and determine reducing sugars 
in an aliquot as directed under VIII, 25. Express the result as per cent of invert 
sugar. 

44 SUCROSE.— TENTATIVE. 
Proceed as directed under VIII, 18. 

45 TOTAL ACIDS.— TENTATIVE. 

Proceed as directed under XIX, 17, employing 5 grams of the sample. Express 
the result as anhydrous citric acid. One cc. of N/10 alkali is equivalent to 0.0064 
gram of anhydrous citric acid. 

46 VOLATILE ACIDS.-TENTATIVE. 

Proceed as directed under XVI, 27, employing 25 grams of the sample, increas- 
ing the amount of water used for the distillation and collecting a correspondingly 
larger amount of distillate. Express the result as acetic acid. One cc. of N/10 
alkali is equivalent to 0.0060 gram of acetic acid. Reserve the neutralized distillate 
for the detection of butyric acid. 

BUTYRIC ACID. 

47 Qualitative Test. — Tentative. 

Evaporate the neutralized distillate, obtained in 46, to dryness on a steam bath. 
Decompose the residue with about 5 cc. of 10% sulphuric acid and note the odor. 

48 FIXED ACIDS.— TENTATIVE. 

Multiply the percentage of volatile acids, 48, by 1.087 and subtract the product 
from the percentage of total acids, 45, to obtain the per cent of fixed acids as citric 
acid. 

Micro-Analysis of Tomato Pulp, Ketchup, Puree and Sauce (Paste). 

49 APPARATUS. 

(a) Compound microscope. — Giving magnifications of approximately 90, 180 and 
500 diameters. These diameters can be obtained by a microscope equipped with 
16 and 8 mm. apochromatic objectives and a X6 and a X18 compensating ocular 
(a X12 ocular may also be used if desired). 

(b) Thoma-Zeiss blood counting cell. 

(C) Special Thoma-Zeiss cell. — With the central disk of 19 mm. diameter for 
making the mold count^. 

50 MOLDS.— TENTATIVE. 

Clean the special Thoma-Zeiss cell so that Newton's rings are produced be- 
tween the slide and the cover-glass. Remove the cover and place, by means of a 
knife blade or scalpel, a small drop of the sample upon the central disk; spread the 
drop evenly over the disk and cover with the cover-glass so as to give an even spread 
to the material. 



XXrV] SPICES AND OTHER CONDIMENTS 325 

It is of the utmost importance that the drop he mixed thoroughly and spread 
evenly, otherwise the insoluble matter, and consequently the molds, are most abun- 
dant at the center of the drop. Squeezing out of the more liquid portions around 
the margin must be avoided. In a satisfactory mount Newton's rings should be 
apparent v/hen finally mounted and none of the liquid should be drawn across the 
moat and under the cover-glass. 

Place the slide under the microscope and examine with about 90 diameters and 
with such adjustment that each field of view represents approximately 1.5 sq. mm. 
of area on the mount. 

Observe each field as to the presence or absence of mold filaments and note the 
result as positive or negative. Examine at least 50 fields, prepared from 2 or more 
mounts. No field should be considered positive unless the aggregate length of the 
filaments present exceeds approximately one sixth the diameter of the field. Cal- 
culate the proportion of positive fields from the results of the examination of all 
the observed fields and report as percentage of fields containing mold filaments. 

51 YEASTS AND SPORES.— TENTATIVE. 

Fill a graduated cylinder with water to the 20 cc. mark, and then add the sample 
till the level of the mixture reaches the 30 cc. mark. Close the graduate, or pour 
the contents into an Erlenmeyer flask, and shake the mixture vigorously 15-20 sec- 
onds. To facilitate thorough mixing the mixture should not fill more than three 
fourths of the container in which the shaking is performed. For tomato sauce or 
pastes, or products running very high in the number of organisms, or of heavy con- 
sistency, 80 cc. of water should be used with 10 cc. or 10 grams of the sample. 
In the case of exceptionally thick or dry pastes, it may be necessary to make an 
even greater dilution. 

Pour the mixture into a beaker. Thoroughly clean the Thoma-Zeiss counting 
cell so as to give good Newton's rings. Stir thoroughly the contents of the beaker 
with a scalpel or knife blade, and then, after allowing to stand 3-5 seconds, remove 
a small drop and place upon the central disk of the Thoma-Zeiss counting cell and 
cover immediately with the cover-glass, observing the same precautions in mount- 
ing the sample as given under 50. Allow the slide to stand not less than 10 min- 
utes before beginning to make the count. Make the count with a magnification 
of about 180 (8 mm. apochromatic objective with the X6 compensating ocular). 

Count the number of yeasts and spores on one half of the ruled squares on the 
disk (this amounts to counting the number in 8 of the blocks, each of which con- 
tains 25 of the small ruled squares) . The total number thus obtained equals the num- 
ber of organisms in 1/60 cmm. if a dilution of 1 part of the sample with 2 parts of water 
is used. If a dilution of 1 part of the sample with 8 parts of water is used, 
the number must be multiplied by 3. In making the counts, the analyst should 
avoid counting an organism twice when it rests on a boundary line between 2 adja- 
cent squares. 

52 BACTESIA.— TENTATIVE. 

Estimate the bacteria from the mounted sample, used in 51 , but allow the sample 
to stand not less than 15 minutes after mounting before counting. Use a magnifi- 
cation of about 500 (8 mm. apochromatic objective and XIS compensating ocular). 
Because of the somewhat clearer definition obtained with the X12 compensating 
ocular, some prefer it to the X18, though the magnification is correspondingly less, 
being about 375. Count and record the number of bacteria in a small area consist- 
ing of 5 of the small sized squares. Move the slide to another portion of the field 



326 METHODS OF ANALYSIS 

and count the number on another similar area. Count 5 such areas, preferably 1 
from near each corner of the ruled portion of the slide and 1 from near the center. 
Determine the average nimiber of bacteria per area and multiply by 2,400,000 which 
gives the number of bacteria per cc. If a dilution of 1 part of the sample with 
8 parts of water instead of 1 part of the sample with 2 parts of water is used in 
making up the sample, then the total count obtained as above must be multiplied 
by 7,200,000. Omit the micrococci type of bacteria in making the count. 

BIBLIOGRAPHY. 

1 Z. anal. Chem., 1892, 31: 525; Conn. Agr. Exp. Sta. Kept., 1898, (II), p. 190. 

2 U. S. Bur. Chem. Bull. 13 (II), p. 165. 

2 Conn. Agr. Exp. Sta. Rept., 1898, (II), p. 187. 

* Winton. Microscopy of Vegetable Foods. 2nd ed., 1916; Vogl. Die wichtig- 
sten vegetabilischen Nahrungs-und Genussmittel. 1899; Tschirch und Oesterle. 
Anatomischer Atlas der Pharmakognosie und Nahrungsmittelkunde. 1900; Greenish 
and Collin. Anatomical Atlas of Vegetable Powders. 1904; Greenish. Microscopical 
Examination of Foods and Drugs. 2nd ed., 1910; Koch. Die Mikroscopische Ana- 
lyse der Drogenpulver. 1900-08. 

» U. S. Bur. Chem. Circ. 68, p. 4. 



XXV. CACAO PRODUCTS. 

1 PREPARATION OF SAMPLE.— TENTATIVE. 

Mix powdered products thoroughly and preserve in tightly stoppered bottles. 
Chill sweet or bitter chocolate until it becomes hard and reduce to a finely granu- 
lar condition by grating or shaving. Mix thoroughly and preserve in a tightly 
stoppered bottle in a cool place. 

2 MOISTURE.— OFFICIAL. 
Proceed as directed under IX, 2. 

3 ASH.-OFFICIAL. 

Proceed as directed under VIII, 4, employing sufficient sample to contain approxi- 
mately 1 gram of water-, sugar- and fat-free material. 

4 ASH INSOLUBLE IN ACID.— TENTATIVE. 

Proceed as directed under XXIV, 5. 

5 SOLUBLE AND INSOLUBLE ASH.— TENTATIVE, 

Proceed as directed under IX, 17, employing sufficient sample to contain ap- 
proximately 1 gram of water-, sugar- and fat-free material. 

6 ALKALINITY OF THE SOLUBLE ASH.— TENTATIVE. 
Proceed as directed under IX, 18. 

7 ALKALINITY OF THE INSOLUBLE ASH.— TENTATIVE. 
Proceed as directed under IX, 19. 

8 TOTAL NITROGEN.— OFFICIAL. 
Determine total nitrogen as directed under I, 18, 21 or 23. 

9 CRUDE FIBER.— TENTATIVE. 

Proceed as directed under VIII, 68, employing sufficient sample to contain ap- 
proximately 1 gram of water-, sugar- and fat-free material, except that both filtra- 
tions should be made upon paper, the washed fiber either being weighed upon a 
tared filter in the usual way or rinsed from the paper into a tared Gooch, dried and 
weighed. 

The residue after fat extraction may be used directly for the crude fiber deter- 
mination in the analysis of commercial cocoa and other finely ground or pulver- 
ized cacao products. If, however, the material is at all granular, it should be re- 
duced to an impalpable powder; otherwise the results will be much too high. The 
pulverization may be satisfactorily performed by grinding with ether, as described 
under 10, treating the extracted residue with the hot 1.25% sulphuric acid and 
proceeding from this point as directed above. 

327 



328 METHODS OF ANALYSIS [Chap 

STARCH. 

10 Direct Acid Hydrolysis. — Tentative. 

Weigh 4 grams of the sample, if unsweetened, or 10 grams if sweetened, into a 
small porcelain mortar, add 25 cc. of ether and grind. After the coarser material 
has settled, decant the ether, together with the fine suspended matter, onto an 11 
cm. paper of sufficiently fine texture to retain the crude starch. Repeat this treat- 
ment until no more coarse material remains. After the ether has evaporated from 
the filter, transfer the fat-free residue to the mortar by means of a jet of cold water 
and rub to an even paste, filtering on the paper previously employed. Repeat this 
process until all the sugar is removed. In the case of sweetened products the fil- 
trate should measure at least 500 cc. Determine crude starch in the extracted 
residue as directed under VIII, 60. 

11 Diastase Method. — Tentative. 

Remove fat and sugar from 4 grams of the sample, if unsweetened, or 10 grams if 
sweetened, as directed under 10. Wash carefully the wet residue into a beaker with 
100 cc. of water, heat to boiling over asbestos with constant stirring and continue 
the boiling and stirring for 30 minutes. Replace the water lost by evaporation and 
immerse the beaker in a water bath kept at 55°-60°C. When the liquid has cooled 
to the temperature of the bath, add 20 cc. of freshly prepared malt extract [VIII, 
61] and digest the mixture for 2 hours with occasional stirring. Boil a second 
time for 30 minutes, dilute, cool and digest as before with another 20 cc. portion 
of the malt extract. Heat again to boiling, cool and transfer to a 250 cc. flask. Add 
3 cc. of alumina cream, make up to the mark and filter through a dry paper. The 
residue on the paper should show no signs of starch when examined microscopically. 
Continue from this point as directed under VIII, 62, beginning with the words 
"Place 200 cc. of the filtrate in a flask with 20 cc. of hydrochloric acid". 

12 FAT.— TENTATIVE. 

Dry 2 grams of the material over sulphuric acid until all the moisture is practi- 
cally removed. (Products rich in fat show a tendency to cake at the temperature 
of boiling water. Hence, drying by means of heat must be avoided.) Extract with 
anhydrous ether in a continuous extractor until no more fat is removed. Grind 
and repeat the extraction. Introduce the ether extract into a tared dish, allow the 
ether to evaporate and dry the residue to constant weight at 100°C. 

The rapid centrifugal method^ though useful and accurate under ordinary con- 
ditions, is unreliable during the summer months or in warm latitudes and has not 
been approved. 

13 FAT CONSTANTS.— TENTATIVE. 

Separate the fat in a manner similar to that described under 15 and determine 
the melting point, index of refraction, iodin absorption, saponification, Reichert- 
Meissl and Polenske numbers as directed under XXIII. Melting point determi- 
nations upon this material do not become normal until the fat has been kept for at 
least 24 hours in a cool place. 

14 MILK FAT IN MILK CHOCOLATE.— TENTATIVE. 

Estimate the amount of milk fat in milk chocolate from the following formula 
based on a Reichert-Meissl number of 0.5 for cocoa butter: 



XXV] CACAO PRODUCTS 329 

^ 24A + 0.5B . ^. , 

^ = = in which 

5 

A = grams of butter fat in 5 grams of mixed fat; 

B = 5 — A = grams of cocoa fat in 5 grams of mixed fat; 

C = Reichert-Meissl number of extracted fat. 

From which the 

f~\ OK 

Weight of butter fat in 5 grams of mixed fat = and the 

4.7 

C — 5 

Per cent of butter fat = per cent of total fat X - 

23.5 

1 5 SUCROSE AND LACTOSE.— TENTATIVE. 

Prepare the sample by chilling well and shaving as finely as possible with a knife. 
Transfer 26 grams of this material to an 8 ounce nursing bottle, add about 100 cc. 
of petroleum ether and shake for 5 minutes. Centrifugalize until the solvent is 
clear. Draw off the same by suction and repeat the treatment with petroleum 
ether. Place the bottle containing the de-fatted residue in a warm place until the 
residual traces of petroleum ether are practically expelled. Add 100 cc. of water, 
shake until all the chocolate is loosened from the sides and bottom of the bottle 
and then shake for 3 minutes longer. Add basic lead acetate solution from a burette 
to complete precipitation, then sufficient water to make the total volume of liquid 
110 cc. Mix thoroughly and filter through a folded filter. Make the direct polari- 
scopic reading "a" in a 200 mm. tube. Precipitate the excess of lead by anhydrous 
potassium oxalate and invert the solution as directed under VIII, 14. Obtain 
the reading of the inverted solution. Multiply the invert reading by 2 to correct 
for dilution "b". From the figures obtained calculate the percentages of sucrose 
(S) and lactose (L) by the formulas 



g ^ (a-b) (110 + x) 
r 

_ ^ i'-' + m) -^ 



142.66- I 



^ in which the value of x is obtained from 

0.79 

0.2244 Ca-21d) . , . , ^, , r j • i,. - j r 

X = - — „ ^^^^ . , pTT-r- in which the value of d is obtained from 

1 - 0.00204 (a - 21d) 

, a— b 
d= 

142.66- 1 

16 CASEIN IN MILK CHOCOLATE.— TENTATIVE. 

It is unnecessary to de-fat the chocolate. Weigh 10 grams of the chocolate 
into a 500 cc. Erlenmeyer flask and add 250 cc. of 1% sodium oxalate solution. Heat 
to boiling and boil gently for a few minutes, then cool, add 5 grams of magnesium 
carbonate and filter. Determine nitrogen in 50 cc. of this filtrate. Pipette 100 cc. 
of the filtrate into a 200 cc. volumetric flask and dilute almost to the mark with 
water. Then precipitate the casein by the addition of 2 cc. of glacial acetic acid 
or 1 cc. of concentrated sulphuric acid. Make to volume, shake, filter and deter- 
mine nitrogen in 100 cc. of the filtrate. The difference between the 2 nitrogen de- 
terminations gives the nitrogen derived from the casein which, multiplied by 6.38, 
gives the amount of casein present in 2 grams of the sample. 



330 METHODS OF ANALYSIS 

17 COLOEING MATTERS.— TENTATIVE. 

Proceed as directed under XI. 

BIBLIOGRAPHY. 
» U. S. Bur. Chem. Bull. 137, p. 103. 



XXVI. COFFEES. 

GREEN COFFEE. 

1 MACROSCOPIC EXAMINATION.— TENTATIVE. 

A macroscopic examination is usually sufficient to show the presence of excessive 
amounts of black and blighted coffee beans, coffee hulls, stones and other foreign 
matter. These can be separated by hand picking and determined gravimetrically. 

2 COLORING MATTERS.— TENTATIVE. 

Shake vigorously 100 grams or more of the sample with cold water or 70% alco- 
hol by volume. Strain through a coarse sieve and allow to settle. Identify 
soluble colors in the solution and insoluble pigments in the sediment as directed 
under XI. 

ROASTED COFFEE. 

3 MACROSCOPIC EXAMINATION.— TENTATIVE. 

Artificial coffee beans are apparent from their exact regularity of form. Roasted 
legumes and lumps of chicory, when present in whole roasted coffee, can be picked 
out and identified microscopically. In the case of ground coffee sprinkle some of 
the sample on cold water and stir lightly. Fragments of pure coffee, if not over- 
roasted, will float, while fragments of chicory, legumes, cereals, etc., will sink imme- 
diately, chicory coloring the water a decided brown. In all cases identify the par- 
ticles that sink, by microscopical examination. 

4 PREPARATION OF SAMPLE.— TENTATIVE. 

Grind the sample and pass through a sieve having holes 0.5 mm. in diameter 
and preserve in a tightly stoppered bottle. 

5 MOISTURE.— TENTATIVE. 

Dry 5 grams of the sample at 105°-110°C. for 5 hours and subsequent periods of 
an hour each until constant weight is obtained. The same procedure may be used, 
drying in vacuo at the temperature of boiling water. In the case of whole coffee, 
grind rapidly to a coarse powder and weigh at once portions for the determina- 
tion without sifting and without unnecessary exposure to the air. 

SOLUBLE SOLIDS. 

6 Winton Method. — Tentative. 

Place 4 grams of the sample in a 200 cc. flask, add water to the mark and allow 
the mass to infuse 8 hours, with occasional shaking; let stand 16 hours long r with- 
out shaking, filter, evaporate 50 cc. of the filtrate to dryness in a flat-bottomed 
dish, dry at 100°C. and weigh. 

7 ASH.— OFFICIAL. 

Prpceed as directed under VIII, 4. 

331 



332 METHODS OF ANALYSIS [Chap. 

8 ASH INSOLUBLE IN ACID.— TENTATIVE. 

Proceed as directed under XXIV, 5. 
g SOLUBLE AND INSOLUBLE ASH.— TENTATIVE. 

Proceed as directed under TK. 17. 

10 ALKALINITY OF THE SOLUBLE ASH.-TENTATIVE. 
Proceed as directed under IX, 18. 

1 1 SOLUBLE PHOSPHORIC ACID IN THE ASH.-TENTATIVE. 

Acidify the solution of soluble ash, obtaiuod in 9, with dilute nitric acid and 
determine phosphoric acid (P205)as directed under I, 6 or 9. 

■|2 INSOLUBLE PHOSPHORIC ACID IN TECE ASH.-TENTATIVE. 

Determine phosphoric acid (P2O6) in the insoluble ash as directed under I, 6 
or 9. 

13 CHLORIN.-OFFICLAL. 
Proceed as directed under III, 18. 

CAFFEIN. 

14 Gorier Method}. — Tentative. 

Moisten 11 grams of finelj^ powdered coffee with 3 cc. of water, allow to stand 
30 minutes and extract with chloroform for 3 hours in a Soxhlet extractor. Evap- 
orate the extract, treat the residue of fat and caffein with hot water, filter through 
a cotton plug and moistened filter paper and wash with hot water. Make up the 
filtrate and washings to 55 cc, pipette off 50 cc. and extract 4 times with chloro- 
form. Evaporate the chloroform extract in a tared flask, dry the caffein at 100°C. 
and weigh. Transfer the residue to a Kjeldahl flask with a small amount of hot 
water and determine nitrogen as directed in I, 18, 21 or 23. To obtain the weight 
of caffein multiply the result by 3.464. 

15 Modified Slahlschmidt Method^. — Tentative. 

Weigh 3.125 grams of the finely powdered sample into a 500 cc. flask, add 225 cc. 
of water (this volume will shrink to about 200 cc. by boiling), attach a reflux con- 
denser and boil for 2 hours. Add 2 grams of dry basic lead acetate [VIII, 13 (C)] 
and boil 10 minutes more. Cool, transfer to a 250 cc. graduated flask, fill to the 
mark, filter through a dry filter, measure 200 cc. of the filtrate into a 250 cc. 
graduated flask and pass hydrogen sulphid through it to remove the excess of lead. 
Make the solution up to the mark and filter through a dry filter. Measure 200 cc. 
of this filtrate into an evaporating dish and concentrate to about 40 cc. Wash the 
concentrated solution with as little water as possible into a small separatory funnel 
and shake out 4 times with chloroform, using 25, 20, 15 and 10 cc, respectively. If 
any emulsion forms, break it up with a stirring rod and run the separated portions of 
chloroform through a 5 cm. filter paper into a small, tared Erlenmeyer flask. Evap- 
orate off the chloroform on the steam bath, or recover the chloroform by attaching 
the flask to a condenser and distilling to a small volume. Dry the fine, white crystals 
of caffein to constant weight at 75°C. Test the purity of this residue by deter- 
mining nitrogen as directed in I, 18, 21 or 23 and multiplying by the factor 3.464. 



XXVI] COFFEES :i33 

18 CRUDE FIBER.-TENTATIVE. 

Proceed as directed under VIII, 68. 

17 STARCH.— TENTATIVE. 

Extract 5 grams of the finely pulvcrizod sample on a hardened filter with 5 suc- 
cessive portions (10 cc. each) of ether; wash with smailf portions* of 9o% alcohol 
by volume until a total of 200 ce. have passed tlirouf^h, place the residue in a 
beaker and proceed as directed under VIII, 62. 

"18 SUGARS.— TENTATIVE. 

Proceed as directed under VIII, 58 and 59. 

"19 PETROLEUM ETHER EXTRACT.-TENTATIVE. 

Dry 2 grams of the coffee at 100°C., extract with petroleum ether (b. p. So'-SCC.) 
for 16 hours, evaporate the solvent, dry the residue at 100°C. and weigh. 

20 TOTAL ACIDITY.— TENTATIVE. 

Treat 10 grams of the sample, prepared as directed under 4,'with 75 cc. of 80% 
alcohol by volume in an Erlenmeyer flask, stopper and allow to stand 16 hours, 
shaking occasionally. Filter and transfer an aliquot of the filtrate (25 cc. in the 
case of green coffee, 10 cc. in the case of roasted coffee) to a beaker, dilute to about 
100 cc. with water and titrate with N/10 alkali, using phenolphthalein as an indi- 
cator. Expre.ss the result as the number of cc. of N/10 alkali required^to neutralize 
the acidity of 100 grams of the sample. 

21 VOLATILE ACIDITY.— TENTATIVE. 

Into a volatile acid apparatus [XVI, 27; Fig. 8] introduce a few glass beads and 
over these place 20 grams of the unground sample. Add 100 cc. of recently boiled 
water to the sample, place a sufficient quantity of recently boiled water in the outer 
flask and distil until the distillate is no longer acid to litmus paper (usually 100 cc. 
of distillate will be collected). Titrate the distillate with N/10 alkali, using phenol- 
phthalein as an indicator. Express the result as the number of cc. of N/10 alkali 
required to neutralize the acidity of 100 grams of the sample. 

Coating and Glazing Substances. 

22 sugar and dextrin.— tentative. 

Introduce 100 grams of the whole coffee into a beaker, add exactly .300 cc. of 
water, stir and allow to stand 5 minutes, with frequent stirring. Filter through a 
dry paper, add carefully to the filtrate sufficient dry lead acetate to precipitate 
all the caffetannic acid, avoiding an excess. Filter through dry paper and re- 
move the lead from the filtrate by the addition of a slight excess of anhydrous 
potassium oxalate. Filter through a dry paper and determine reducing sugars as 
invert sugar in 50 cc. of the filtrate, as directed in VIII, 25. Invert a 75 cc. aliquot 
of the filtrate as directed under VIII, 14. Cool, nearly neutralize with sodium 
hydroxid solution, make up to 100 cc. and determine reducing sugars as invert sugar 
in the resulting solution, as directed under VIII, 25. Measure a 100 cc. aliquot 
of the filtrate into a 200 cc. flask, add 10 cc. of 25% hydrochlorio acid and hy- 
drolyze as directed under VIII, 60. Cool, neutralize with sodium hydroxid solu- 
tion, make up to volume, filter through a dry paper and determine reducing sugars 
as invert sugar in 50 cc. of the filtrate as directed under VIII, 25. Calculate the 



334 METHODS OF ANALYSIS 

reducing sugars in each instance to per cent by weight of the original coffee. Cal- 
culate sucrose from the reducing sugars before and after inversion as directed in 
VIII, 1 8, and calculate dextrin as follows : Subtract the reducing sugars after in- 
version from the reducing sugars after hydrolysis, multiply the difference by the 
factor 0.9561 to convert the result to dextrose and then by 0.9 to convert to dextrin. 
In some instances the presence of sucrose in the water extract may be verified 
by polarization. The presence of dextrin in the water extract may be verified by 
polarization as directed under IX, 25, and by the erythro-dextrin test [IX, 47] 
performed on the water extract previous to clarification with lead acetate. 

23 EGG ALBUMEN AND GELATIN.— TENTATIVE. 

Treat 100 grams of the whole coffee with 500 cc. of water and allow to stand with 
frequent stirring for 5 minutes. Filter and treat separate portions of the filtrate 
with (1) a strong solution of tannic acid; (2) Millon's reagent [XV, 9]; (3) by 
boiling. In the presence of egg albumen a more or less heavy precipitate will 
be formed in each case. As a confirmatory test, treat an aliquot of the filtrate with 
an excess of tannic acid solution, add a little salt if necessary to secure flocculation 
of the precipitate, filter and, without washing, introduce the paper and its con- 
tents into a Kjeldahl flask and determine nitrogen. By this method coffee not 
coated with albumen or gelatin will yield less than 10 mg. of nitrogen per 100 grams 
of sample. 

24 CmCORY INFUSION.— TENTATIVE. 

Cover 100-150 grams of the whole coffee with water, allow to soak 2-3 minutes, 
stirring frequently, and drain the aqueous washings through a coarse sieve. Wash 
the coffee upon the sieve with about 100 cc. of water and centrifugalize the com- 
bined washings. Decant the clear liquid from the sediment, drain almost dry upon 
filter paper, then mount the sediment in chloral hydrate [XXTV, 20 (f)] and exam- 
ine under the microscope for elements of chicory. 

FATS AND WAXES. 

25 Spath Method^. — Tentative. 

Treat 100-200 grams of the beans with low boiling petroleum ether for 10 min- 
utes, pour off the petroleum ether and repeat the process. Filter the combined 
petroleum ether extracts, evaporate and determine the index of refraction and the 
saponification number of the residue, as directed under XXIII, 6 and 20. 

BIBLIOGRAPHY. 

1 Ann., 1908, 358:327. 

2 Allen. Commercial Organic Analysis. 4th ed., 1909-14, 6: 607. 

3 Forschb. uber Lebensm., 1895, 2: 223. 



XXVII. TEA. 

"I DUST, STEMS AND FOREIGN LEAVES.— TENTATIVE. 

Place 1 gram of the tea in a 300 cc. casserole, add 200 cc. of boiling water and 
allow to stand 15 minutes. This treatment will cause the leaves to unroll, and a 
macroscopic examination will reveal the presence or absence of dust or stems, while 
the leaves will be in condition for examination as to their form and structured 

2 PREPARATION OF SAMPLE.— TENTATIVE. 

Grind the sample and pass it through a sieve having circular openings 0.5 mm. 
in diameter. 

3 MOISTURE.— TENTATIVE. 
Proceed as directed under IX, 2. 

4 WATER EXTRACT^.- TENTATIVE. 

To 2 grams of the original sample in a 500 cc. Erlenmeyer flask add 200 cc. of hot 
water and boil over a low flame for an hour. The flask should be closed with a rub- 
ber stopper through which passes a glass tube 18 inches long for a condenser. The 
loss from evaporation should be replaced from time to time by the addition of 
hot water. Filter through a tared filter and wash the residue until the filtrate meas- 
ures 500 cc, stirring the contents of the filter throughout the process to facilitate 
the filtering. Dry the filter paper and residue in the funnel in the steam oven until 
the excess of water is removed, transfer paper and contents to a tared weighing 
bottle and dry to constant weight at 100°C. 

5 ASH.— OFFICIAL. 
Proceed as directed under VIII, 4. 

6 SOLUBLE AND INSOLUBLE ASH.— TENTATIVE. 
Proceed as directed under IX, 17. 

7 ASH INSOLUBLE IN ACID.— TENTATIVE. 
Proceed as directed under XXIV, 5. 

8 ALKALINITY OF THE ASH.— TENTATIVE. 

Determine the alkalinity of the soluble and insoluble ash as directed under IX, 
18 and 19. 

9 PHOSPHORIC ACID IN THE ASH.— TENTATIVE. 

Determine phosphoric acid (P2O5) in the soluble and insoluble ash as directed 
under XXVI, 11 and 12. 

10 PETROLEUM ETHER EXTRACT.— TENTATIVE. 
Proceed as directed under XXVI, 19. 

335 



336 MKTIIODS OF ANALYSIS [Chap. 

11 PROTEIN. TENTATIVE. 

iJc'LonniiK; nilro;^oii an diroctcd under I, 18, 21 or 23. ,Su!)tract t!io percentage 
of nitrogen present as cafrein from the percentage of total nitrogen to obtain the 
percentage of nitrogen present as protein. Multiply this re.sult by 0.25 to obtain 
the percentage of protein. • 

12 CRUDE FIBER.— TENTATIVE. 
l*rocc(!d as directed under VIII, 68. 

13 VOLATILE OIL. -TENTATIVE. 

Add 100 grams of tea to 800 cc. of water, distil, extract the distillate several times 
with petroleum ether, transfer the combined petroleum ether extracts to a tared 
dish, evaporate at room temperature, dry in a desiccator and weigh. 

CAFFEIN. 

14 Modified Stahlschmidl Method. — Tentative. 
IVoceed us directed und(!r XXVI, 15. 

TANNIN. 
Proctor Modification of the Ldwenlhal Method'^. — Tentative. 

15 UEAGKNTS. 

(a) I'otatisium yermanganate solution. — Make up a solution containing 1.33 grams 
per liter and obtain its equivalent in terms of N/IO oxalic acid. 

(b) N/W oxalic arid. 

(C) Indigo carmine Holulion. — Make up a solution containing G grams of indigo 
carmiiH! (fre(; from indigo blue) and 50 cc. of concentrated sulphuric acid per liter. 

(d) (k'latin solution. — Soak 25 grams of gelatin for an hour in saturated sodium 
chlorid solution, heat (intil the gelatin is dissolved and make up to 1 liter after 
cooling. 

(e) Acid .sodium chlorid solution. — Acidify 975 cc. of saturated sodium chlorid solu- 
tion with 25 cc. of concentrated sulphuric acid. 

(f) I'onulcrcd kaolin. 



16 



DETERMINATION. 



Boil 5 grams of tlu; tea for 30 minutes with 400 cc. of water; cool, transfer to a 
600 cc. graduated flask and make up to the mark. To 10 cc. of the infusion, fdtered 
if not clear, add 25 cc. of the indigo carmine solution and about 750 cc. of water. 
Add from a burette the potassium i)ermanganate solution, a little at a time while 
stirring, until the color becomes light green, then drop by drop, until the color 
changes to bright yellow or to a faint pink at the rim. Designate the number of 
cc. of i)ernianganato used as "a". 

Mix 100 vc. of the clear infusion of tea with 50 cc. of the gelatin solution, 100 cc. 
of the acid sodium chlorid solution and 10 grams of the powdered kaolin, and shako 
several minutes in a stoppered flask. After settling decant through a filter. Mix 
26 cc. of the filtrate with 25 cc. of the indigo carmine solution and about 750 cc. of 
water and titrate with permanganate as before. The number of cc. of permanganate 
usedsubtractiul from that obtained above, "a", gives the amount of permanganate 
required to oxidize the taimin. One cc. of N/10 oxalic acid is equivalent approxi- 
mately to 0.001157 gram of tannin (gallotannic acid). 



XXVII] TEA 337 

Facing. 

17 general.— tentative. 

Mineral pigments may be detected in the aHli, or the tea may be shaken up with 
a large vohnne of water, and the water separated from the leaves by a sieve, when 
the insoluble mineral substances used in facing will settle and can be removed by 
filtration for further examination, as directed under XI, 1, the catechu and other 
soluble substances being in the filtrate. 

18 PARAFFIN AND WAXY SUBSTANCES.-TENTATIVE. 

Spread a qiiantity of the tea between 2 sheets of unglazed, white paper and place 
thereon a hot iron. Any greasy substance will stain tin; paj)er'*. 

PIGMENTS USED FOR COLORING OR FACING. 

19 Read Method^. — Tentative. 

Place 60 grams of the tea in a GO mesh, .'>-G inch sieve, provided with a top. Sift 
a small quantity (approximately 0.1 gram) of the dust upon a i)iece of semi-glazed, 
white paper about 8 by 10 inches. To obtain the requisite amount of dust, it is 
sometimes necessary to rub the leaf gently against the; bottom of the sieve, but this 
must not be done until the sieve has been well shaken over the paper. Place the 
paper on a plain, firm surface, preferably glass or marble;, and crush th(! dust by 
pressing firmly upon it a flat steel spatula about .5 inches long. Repeat the crush- 
ing process until the tea dust is ground almost to a powder when particles of color- 
ing matter, if present, become visible as streaks on the paper. Brush off the 
loose dust and examine the paper by means of a simple lens magnifying 7 J diame- 
ters. In distinguishing these particles and streaks bright light is essential. In 
many cases the character of the pigment is indicated by the behavior of these 
streaks when treated with reagents and examined under a microscope. 'J'hc 
crushed particles of natural leaf in either black or green tea appear in such 
quantity that there is no chance of mistaking them for coloring or facing material. 
This test should be repeated using black, semi-glazed paper for facings such as talc, 
gypsum, barium sulphate or clay. 

BIBLIOGRAPHY. 

1 U. S. Bur. Chem. Bull. 1.3 fVII); Villiers and Colin. Trait6 des Alterations et 
Falsifications des Substances Alimentaires. 2nd ed., 1909-11. 
^ U. S. Bur. Chem. Bull. 105, p. 48. 
» Ibid., 13 (VII), p. 890. 

♦ U. S. Treas. Dept., T. D. 35244, March 23, 1915. 
6 Ibid.; Proc. Eighth Intern. Cong. Appl. Chem., 1912, 18: 301. 



XXVIII. BAKING POWDERS AND THEIR INGREDIENTS. 

1 PREPARATION OF SAMPLE.— TENTATIVE. 

Remove the entire sample from the package, mix carefully and pass through a 
20-40 mesh sieve. 

TOTAL CARBON DIOXID. 

2 General Method. — Tentative. 

Make the determination by the absorption method, employing any apparatus 
which gives accurate results when checked with pure calcite. Whatever appara- 
tus is chosen, the tubes and materials used for absorbing and drying the carbon 
dioxid may be varied according to the preference of the analyst. Use 0.25-1 gram 
of sodium or calcium carbonate, according to the amount of absorbent employed, 
and in the case of baking powder 0.50-2 grams. 

Method Using Knorr's Apparatus. — Tentative. 

3 REAGENTS. 

(a) 50% potassium hydroxid solution. 

(b) Soda lime. — Finely granulated and freed from dust by sifting. 

4 APPARATUS. 




FIG. 14 KNORR'S APPARATUS FOR THE DETERMINATION OF CARBON DIOXID. 

This consists of a flask (A), fitted by means of a ground-glass joint with a glass 
connection through the upper part of which passes a dropping funnel (-B), and 
joined at the side with a Liebig condenser (D). The mouth of the dropping funnel 

339 



340 METHODS OF ANALYSIS [Chap. 

(B) is connected by means of a perforated stopper with a soda lime tube (C). The 
upper end of the Liebig condenser is connected by a rubber joint with a Geissler 
bulb (E), containing sulphuric acid for drying the gas passing into the next Geissler 
bulb (F), connected with (E), and containing strong potassium hydroxid solution 
(1 to 2). The bulb (F) is connected with a third Geissler bulb (G), containing sul- 
phuric acid for the absorption of moisture escaping from F. A fourth Geissler 
bulb (H) is attached to G as a precaution to prevent moisture from the air being 
absorbed by G. H is connected with an aspirator. Many analysts prefer to re- 
place the bulb (F) by 2 U-tubes filled with sifted soda lime. 

5 DETERMINATION. 

Place 0.5-2 grams of the baking powder, the amount depending upon the per- 
centage of carbon dioxid present, in the flask (A), which must be perfectly dry. 
Close the flask with the stopper which carries the funnel tube and the tube con- 
necting with the absorption apparatus. Weigh separately the Geissler bulbs (F) 
and ((?) and attach them to the apparatus. If 2 soda lime tubes are employed, 
weigh them separately and fill the first anew when the second increases materially 
in weight. Nearly fill the funnel tube (B) with hydrochloric acid (sp. gr. 1.1) and 
place the soda lime tube (C) in position. Then aspirate air through the Geissler 
bulbs at a rate of about 2 bubbles per second. Open the stopper of the funnel and 
allow the acid to run slowly into the flask, care being taken that the evolution of 
gas be so gradual as not to materially increase the current through the Geissler 
bulbs. After all the acid has been introduced, close the stop-cock in B, continue 
the aspiration and heat gradually the contents of the flask to boiling. While the 
flask is being heated the aspirator tube may be removed, although many analysts 
prefer, when using ground-glass joints, to aspirate during the entire operation. 
Continue the boiling for a few minutes after the water has begun to condense in 
D, then remove the flame, open the stop-cock in tube (5) and allow the apparatus 
to cool with continued aspiration. Remove the absorption bulbs (F) and (G) and 
weigh. The increase in weight is due to carbon dioxid. 

Method Using Heidenhain's Apparatus. — Tentative. 

6 REAGENTS, 

(a) Calcium chlorid. — Use calcium chlorid dehydrated at 200°C., but not fused. 
Grind it coarsely in a coffee mill and sift through No. 18 wire gauze to remove the 
extremely coarse, and through No. 30 wire gauze to remove the very fine, particles. 

(b) Soda lime. — Grind and sift the soda lime' for the weighed tubes as described 
above. It should not be too dry, as it must not absorb moisture to a greater degree 
than the calcium chlorid. 

7 APPARATUS^. 

This consists of a cylinder (A), filled with soda lime to remove carbon dioxid 
from the air passing through the apparatus. A thick layer of cotton at the upper 
end prevents soda lime dust from being carried over. Connect the cylinder (A) 
by means of a perforated rubber stopper and a bent glass tube having a stop-cock 
(B) and a capillary constriction (C) with a short piece of rubber tubing to which 
is attached a short piece of glass tubing {E), fitted with a perforated rubber stopper. 
The latter fits tightly into the constriction of the funnel tube (D). The funnel of 
the latter is cylindrical in shape, f inch in diameter at the upper end, f inch at the 
lower end and 4 inches long, the rubber stopper of E fitting into the constriction. 



XXVIII] 



BAKING POWDERS 



341 



The stem of the funnel tube (D) passes through a doubly perforated rubber stopper 
almost to the bottom of the evolution flask (F), which is ordinarily of 150 cc. 
capacity but, in the case of foaming liquids, may hold 300 cc. Through the second 
perforation in the stopper connect the evolution flask (F) with a reflux condenser 
(G), consisting of a J inch glass tube around which is wound a small lead pipe carry- 
ing a current of cold water. To the upper end of the condenser attach a U-tube 
containing a little calcium chlorid (to be renewed when it has liquefied) to retain the 
bulk of the moisture. Connect this U-tube with a second U-tube (H), filled with 
coarse calcium chlorid, and this in turn with a third U-tube (/v), filled at I with a 3 
inch column of pumice stone impregnated with copper sulphate and completely de- 
hydrated at 150°C., the remainder of the tube being filled with fine calcium chlorid. 
Connect the U-tube {K) with a bent glass tube having a stop-cock (L) which is 
closed when the apparatus is not in use. Next attach the absorption U-tubes (Af ) 
and {N) which are § inch in diameter and 5 inches long, the first filled mainly with 
soda lime but containing a little calcium chlorid at the end where the air current 




FIG. 15. HEIDENHAIN'S APPARATUS FOR THE DETERMINATION OF 
CARBON DIOXID. 

enters, the second filled one half with soda lime and one half with calcium chlorid, 
the latter being placed at the side where the air current leaves. Connect N with 
a guard tube (0), filled with calcimn chlorid on the side toward N and with soda 
lime on the side toward P, the latter being a small U-tube trapped with glycerol to 
indicate the passage of the air current. Connect P with a safety bottle {R), to 
receive any water which may be sucked back from the aspirator, and connect R 
with the aspirator (S), a 4 liter Mariette bottle. 

The tubes (M) and (A^) should hold about 20 grams, making the capacity of M 
for carbon dioxid almost 1 gram and that of N for moisture 0.2 gram. M should 
be refilled when its weight has increased 0.75 gram and N after an increase of 0.1 
gram in weight. 

Use the best grade of rubber for all connections, applying a trace of castor oil 
as a lubricant. For connections of the weighed tubes use rubber tubing boiled in 
weak lye, washed and dried. Apply also a little castor oil, which is thoroughly 
wiped off again before connecting the tubing. 

Before using the apparatus fill H and K with carbon dioxid in order to saturate 
the alkalinity of the calcium chlorid and exhaust after several hours. 



342 METHODS OF ANALYSIS [Chap. 

8 DETERMINATION. 

In order to find the allowable rapidity of the air current employed during the 
determination, proceed as follows: Charge the apparatus exactly as for an analysis 
leaving out the carbonate. Begin to aspirate at the rate of about 50 cc. per minute. 
After 2 liters have been aspirated weigh the tubes, M and N. If they have lost in 
weight, repeat the experiment with 40 cc. per minute, and so on until the weight of 
the tubes remains constant. If the work has been done with due precaution, the 
first tube should have lost just as much as the second has gained. Do not exceed the 
safe speed thus found. 

Weigh the tubes M and N at the air temperature of the balance room. Shortly 
before weighing open the tubes for a moment to allow equalization of air. Note 
the thermometer and barometer readings. Connect the tubes with the apparatus 
and test the tightness of the joints by closing A at the bottom, opening all the cocks, 
starting the aspirator, and observing P, in which the liquid should soon come to a 
standstill. Then disconnect the aspirator, close B, remove F, put in the substance, 
using about 1 gram of sodium carbonate or calcium carbonate or about 2 grams of 
baking powder, connect F, and start the condenser {G). Introduce 50 cc. of 10% 
hydrochloric acid through D, lifting E slightly and allowing only small quantities 
of the dilute acid to enter at a time. Light the burner under F, heat to boiling 
and reduce the flame to keep the liquid just at the boiling point. If no more air 
passes P, start the aspiration. When the water stops running from S, open B care- 
fully and adjust the outflow of the aspirator by raising or lowering the syphon to 
one half the safe speed. 

After M has become cool increase the current to the full safe speed and aspirate 
altogether 3 liters, continuing boiling to the end of the aspiration. After the tubes 
have assumed the temperature of the balance room, open for a moment and weigh. 
When extreme accuracy is desired, note again the thermometer and barometer 
readings and apply correction according to the following formula: 

- (A2 - Ai) X T and + (B^ - B^ X B in which 

A^ = the temperature at first weighing in degrees C. ; 
A^ = the temperature at second weighing in degrees C. ; 
B^ = the air pressure at first weighing in mm.; 
B* = the air pressure at second weighing in mm. ; 

T and B are constants found from the following formulas: 

T = V X 0.0000039 gram; 

B = V X 0.0000015 gram in which 

0.0000039 = change in weight of 1 cc. of air for 1°C.; 
0.0000015 = change in weight of 1 cc. of air for 1 mm. pressure; 

and the value of V is obtained from 

2.7 2.0 8.5 ' 

representing the differential volume affected by temperature and pressure and being 
a constant for the tubes and in which 



XXVIII] BAKING POWDERS 343 

G = the weight of the empty tubes; 

F = the weight of the fillings; 
2.7 = the specific gravity of glass; 
2.0 = the specific gravity of filling; 
8.5 = the specific gravity of brass; 

G F 

^-y + — = volume of tubes and fillings; 

G + F 

— ^-=— = volume of brass weights. 
o.o 

9 RESIDUAL CARBON DIOXID'.— TENTATIVE, 

Weigh 2 grams of the baking powder into a flask suitable for the subsequent 
determination of carbon dioxid, add 20 cc. of cold water and allow to stand 20 min- 
utes. Place the flask in a metal drying cell surrounded by boiling water and heat, 
with occasional shaking, for 20 minutes. 

To complete the reaction and drive off the last traces of gas from the semi-solid 
mass, heat quickly to boiling and boil for a minute. Aspirate until the air in the 
flask is thoroughly changed, and determine the residual carbon dioxid by absorption, 
as directed under 5 or 8. 

The process described^ based on the methods of McGill* and Catlin^, imitates 
as far as practicable the conditions encountered in baking but in such a manner that 
concordant results may be readily obtained on the same sample and comparable 
results on different samples. 

10 AVAILABLE CARBON DIOXID.— TENTATIVE. 
Subtract the residual carbon dioxid from the total. 

1 1 ACIDITY.— TENTATIVE. 

(For cream of tartar and its substitutes.) 

Dissolve 1 gram of the sample in hot water and titrate with N/5 potassium hy- 
droxid, using phenolphthalein as an indicator. 

TARTARIC ACID, FREE OR COMBINED. 

1 2 Wolff Method^— Tentative. 
(Applicable in the presence of phosphates.) 

Shake repeatedly about 5 grams of the sample with about 250 cc. of cold water 
in a flask and allow the insoluble portion to subside. Decant the solution through 
a filter and evaporate the filtrate to dryness. Powder the residue, add a few drops 
of 1% resorcin solution and about 3 cc. of strong sulphuric acid and heat slowly. 
Tartaric acid is indicated by a rose-red color which is discharged on dilution with 
water. 

TOTAL TARTARIC ACID, 

13 Goldenherg-Geromont-Heidenhahi Method. — Tentative. 
(Applicable only in the absence of aluminiiun salts, calcium salts and phosphates.) 

Into a shallow 6 inch porcelain dish weigh out 2 grams of the sample and suffi- 
cient potassium carbonate to combine with all the tartaric acid not in the form of 
potassium bitartrate. Mix thoroughly with 15 cc. of cold water and add 5 cc. of 
99% acetic acid. Stir for 30 seconds with a glass rod bent near the end. Add 100 
cc. of 95% alcohol, stir violently for 5 minutes, and allow to settle at least 30 min- 



344 METHODS OF ANALYSIS [Chap. 

utes. Filter on a Gooch crucible with a thin layer of paper pulp and wash with 95% 
alcohol until 2 cc. of the filtrate do not change the color of litmus tincture diluted 
with water. Place the precipitate in a small casserole, dissolve in 50 cc. of hot water 
and add N/5 potassium hydroxid, leaving it still strongly acid. Boil for a minute. 
Finish the titration, using phenolphthalein as an indicator and correct the reading 
by adding 0.2 cc. One cc. of N/5 potassium hydroxid, under the above conditions, 
is equivalent to 0.02641 gram of tartaric anhydrid, 0.03001 gram of tartaric acid, 
or 0.03763 gram of potassium bitartrate. Standardize the N/5 potassimn hydroxid 
by means of pure potassium bitartrate. 

The accuracy of this method is indicated by the agreement of the percentages of 
potassium bitartrate in cream of tartar powders containing no free tartaric acid, 
obtained by calculation from the tartaric acid, with those obtained by calculation 
from the potassium oxid^. 

FREE TARTARIC ACID. 

14 Qualitative Test. — Tentative. 

Extract 5 grams of the sample with absolute alcohol and evaporate the alcohol 
from the extract. Dissolve the residue in dilute ammonium hydroxid, transfer to 
a test tube, add a good sized crystal of silver nitrate and heat gently. Tartaric 
acid is indicated by the formation of a silver mirror. If desired, the absolute alco- 
hol extract may be tested as directed under 1 2. 

15 Quantitative Method. — Tentative. 

Calculate the percentage of tartaric anhydrid combined with the potash as bi- 
tartrate, if any, and subtract this from the percentage of total tartaric anhydrid. 
The difference is the tartaric anhydrid originally added as the free acid, although, 
if the sample has been kept for a long time or has been improperly stored, a portion 
or all of this acid may exist at the time of analysis as the sodium salt resulting from 
the reaction in the can with the sodium bicarbonate. Multiply by 1.137 to obtain 
the percentage of tartaric acid. 

■|g POTASSIUM BITARTRATE.— TENTATIVE. 

If, as is usually the case, potassium bitartrate is the only potassium salt present, 
multiply the percentage of total potash, determined as directed under 24, by 3.994. 

STARCH. 

17 Direct Inversion Method. — Tentative. 

(For all baking powder ingredients free from lime.) 

Weigh 5 grams of the powder into a 500 cc. graduated flask and proceed as directed 
under VIII, 60. 

18 Indirect Method^. — Tentative. 

(For phosphate, alum phosphate and all other baking powders containing lime.) 

Mix 5 grams of the powder with 200 cc. of 3% hydrochloric acid in a 500 cc. grad- 
uated flask and allow the mixture to stand for an hour, with frequent shaking. 
Filter on an 11 cm. hardened filter, taking care that a clear filtrate is obtained. 
Rinse the flask once without attempting to remove all the starch, and wash the 
paper twice with cold water. Carefully wash the starch from the paper back into 
the flask with 200 cc. of water. Add 20 cc. of 25% hydrochloric acid and proceed as 
directed under VIII, 60. 



XXVIII] BAKING POWDERS 345 

The treatment with 3% hydrochloric acid, without dissolving the starch, removes 
effectively the lime, which otherwise would be precipitated as tartrate by the 
alkaline copper solution. 

19 Modified McGill Method. — Tentative. 

Digest 1 gram of the powder with 150 cc. of 3% hydrochloric acid for 24 hours 
at room temperature, with occasional shaking. Filter on a Gooch crucible, wash 
thoroughly with cold water and then once each, with alcohol and ether. Dry at 
110°C. (4 hours is usually sufficient), cool and weigh. Burn off the starch, weigh 
again and determine the starch by difference. 

The results by this method on cream of tartar powders and tartaric acid pow- 
ders agree closely with those obtained by copper reduction. On phosphate, alum 
and alum-phosphate powders the results are usually satisfactory, but in some 
instances they may be over 2% too high. 

ALUM IN THE PRESENCE OF PHOSPHATES". 

20 Qualitative Test. — Tentative. 

(a) In baking powder. — Burn about 2 grams of the sample to an ash in a porce- 
lain dish. Extract with boiling water and filter. Add to the filtrate a few drops 
of ammonium chlorid solution. A flocculent precipitate indicates alum. 

(b) In cream of tartar. — Mix about 1 gram of the sample with an equal quantity 
of sodium carbonate, burn to an ash and proceed as in (a). 

ASRi". 

21 INSOLUBLE ASH AND PREPARATION OF SOLUTION.— TENTATIVE. 

Char 5 grams of the sample in a platinum dish at a heat below redness. Boil the 
carbonaceous mass with dilute hydrochloric acid, filter into a 500 cc. graduated 
flask and wash with hot water. Return the residue, together with the paper, to 
the platinum dish and burn to a white ash. Boil again with hydrochloric acid, 
filter, wash, unite the 2 filtrates and dilute to 500 cc. 

Incinerate the residue after the last filtration and determine the ash insoluble 
in acid. 

22 IRON AND ALUMINIUM.— TENTATIVE. 

Draw a 100 cc. aliquot of the solution, prepared as directed in 21 , and separate 
silica, if necessary. Mix the solution with sodium phosphate solution in excess. 
Add ammonium hydroxid until a permanent precipitate is obtained, then hydro- 
chloric acid, drop by drop, until the precipitate is dissolved. Heat the solution 
to about 50°C., mix with a considerable excess of 50% ammonium acetate solution 
and 4 cc. of 80% acetic acid. 

As soon as the precipitate of aluminium phosphate, mixed with iron phosphate, 
has settled, collect on a filter, wash with hot water, ignite and weigh. 

Fuse the mixed phosphates with 10 parts of sodium carbonate, dissolve in dilute 
sulphuric acid, reduce with zinc, and determine the iron by titration with a standard 
permanganate solution. In the same solution determine the phosphoric acid, as 
directed under I, 6 or 9. To obtain the weight of alumina (AI2O3) subtract the 
sum of the weights of ferric oxid (FeaOa) and phosphorus pentoxid (P2O6) from the 
weight of the mixed phosphates. 



346 METHODS OF ANALYSIS [Chap. 

23 CALCIUM.— TENTATIVE. 

Heat the combined filtrate and washings, obtained in 22, to 50°C. and add an 
excess of ammonium oxalate solution. Allow to stand in a warm place until the 
precipitate has settled, filter, wash the precipitate with hot water, dry, ignite over 
a Bunsen burner and finally over a blast lamp. Cool in a desiccator and weigh as 
calcium oxid. 

24 POTASSIUM AND SODIUM.— TENTATIVE. 

Evaporate an aliquot of the solution, prepared as directed under 21, nearly 
to dryness to remove the excess of hydrochloric acid, dilute and heat to boiling. 
While still boiling add barium chlorid solution so long as a precipitate forms and 
then enough barium h3fdroxid solution to make the liquid strongly alkaline. As 
soon as the precipitate has settled, filter and wash with hot water, heat the filtrate 
to boiling, add sufficient ammonium carbonate solution (1 part of ammonium car- 
bonate in 5 of 2% ammonium hydroxid solution) to precipitate all the barium, 
filter and wash with hot water. Evaporate the filtrate to dryness and ignite the 
residue below redness to remove ammonium salts. Add to the residue a little 
water and a few drops of ammonium carbonate solution. Filter into a tared plat- 
inum dish, evaporate, ignite below redness and weigh the mixed potassium and 
sodium chlorids. 

Determine potassium in the mixed chlorids as directed in I, 45, beginning with 
"Digest the residue with hot water, filter through a small filter". Calculate the 
potassium so found to its equivalent of potassium chlorid and subtract this from 
the weight of the mixed chlorids to obtain the weight of sodium chlorid. 

25 PHOSPHORIC ACID.— OFFICIAL. 

Mix 5 grams of the sample with a little magnesium nitrate solution, dry, ignite, 
dissolve in dilute hydrochloric acid and dilute the solution to a definite volume. 
In an aliquot of the solution determine phosphoric acid as directed under I, 6 or 9. 

26 SULPHURIC ACID' 1.— TENTATIVE. 

Boil 5 grams of the sample gently for li hours with a mixture of 300 cc. of water 
and 15 cc. of concentrated hydrochloric acid. Dilute to 500 cc, draw off a 100 cc. 
aliquot, dilute considerably, precipitate with 10% barium chlorid solution, filter 
the precipitated barium sulphate on a Gooch, wash with hot water, dry, ignite and 
weigh. < 

27 AMMONIA.— TENTATIVE. 

Introduce 2 grams of the sample into a distillation flask, add 300-400 cc. of water 
and an excess of sodium hydroxid solution, connect with a condenser and distil into 
a measured amount of standard acid. Titrate the excess of acid in the distillate 
with standard alkali, using methyl red or cochineal as an indicator. 

Ammonia alum is often an ingredient of cream of tartar substitutes and baking 
powders, and ammonium carbonate is occasionally present in baking powders. 

LEAD. 

Method I. Colorimetric Method^-. — Tentative. 

(Applicable in the absence of alum and phosphates. Approximate method for 

preliminary work.) 

28 REAGENTS. 

(a) Sodiujri bisulphite solution. — Dissolve 10 grams of anhydrous sodium car- 
bonate in sufficient water to make 100 cc. and pass sulphur dioxid into the solution 



XXVni] BAKING POWDERS 347 

until carbon dioxid is no longer evolved. Dilute a little of this solution with 10 
volumes of water as needed in the determination. 

(b) 10% potassium cyanid solution. 

(C) Standard lead solution.—Dissolve 1.6 grams of crystallized lead nitrate, pre- 
viously dried over sulphuric acid, in a liter of water containing a few drops of dilute 
nitric acid. One cc. of this solution is equivalent to 1 mg. of metallic lead. Dilute 
1 cc. of this solution to 100 cc. immediately before use in making up the color 
standards. 

(d) Lead-free tartrate solution. — Dissolve 200 grams of tartaric acid in about 500 
cc. of hot water, cool, add 40 cc. of the sodium bisulphite solution, heat to incipient 
boiling and test a few drops of the solution with potassium sulphocyanate solution 
to ascertain if all the iron is reduced to the ferrous state, repeating the treatment 
with about 10 cc. of the sodium bisulphite solution in case ferric iron is still present. 
Cool, add 20 cc. of the 10% potassium cyanid solution, and then strong ammonium 
hydroxid solution until the solution is distinctly alkaline to litmus paper. Boil 
until the solution is clear, cool, add 2 cc. of freshly prepared, colorless ammonium 
sulphid solution, dilute to 1 liter and allow to stand overnight. Filter to remove 
the precipitated sulphids, boil the filtrate until hydrogen sulphid is removed, cool 
and dilute to 1 liter with water. 



29 



PREPARATION OF SOLUTION. 



(a) Baking powder. — Weigh 20 grams of the sample into a 250 cc. casserole, add 
water a little at a time with stirring until foaming ceases, then hydrochloric acid 
(1 to 1) a little at a time until all the carbonate is decomposed and finally 5 cc. 
excess of the hydrochloric acid. Cover with a watch glass and digest on a steam 
bath until all the starch is hydrolyzed as shown by testing 1 or 2 drops of the mix- 
ture with iodin. Filter through a folded filter and wash the filter several times with 
small portions of hot water. Treat the residue on the filter with several small por- 
tions of hot nitric acid (sp. gr. 1.2), collect the acid solution in a separate, small 
porcelain dish, evaporate this solution to dryness on a water bath and expel nitric 
acid by several treatments and evaporations with a few drops of concentrated 
hydrochloric acid. Rinse the contents of the dish through a small filter into the 
main solution and make up to 100 cc. 

(b) Tartaric acid and cream of tartar. — Dissolve 100 grams of the sample in hot 
water, add 50 cc. of imirochloric acid (1 to 1), filter into a liter graduated flask, 
wash the filter several times with water, and then treat the residue on the filter 
with several small portions of hot nitric acid (sp. gr. 1.2), collect the acid solution 
in a separate, small porcelain dish, evaporate this solution to dryness on a water 
bath and expel nitric acid by several treatments and evaporations with a few drops 
of concentrated hydrochloric acid. Rinse the contents of the dish through a 
small filter into the main solution, finally diluting the combined filtrates and wash- 
ings to a liter. 

30 DETERMINATION. 

Introduce 50 cc. of the solution, prepared as directed in 29, into a beaker, add 
2 cc. of the sodium bisulphite solution, heat to incipient boiling, and test a few 
drops of the solution with potassium sulphocyanate to determine if all the iron is 
reduced to the ferrous state, repeating the treatment with the sodium bisulphite 
solution if ferric iron is still present. Cool, add 1 cc. of the 10% potassium cyanid 
solution and neutralize to litmus with strong ammonium hydroxid solution; finally 
add an excess of 1 cc. of the last reagent. Boil gently until clear and colorless, cool 



348 METHODS OF ANALYSIS [Chap. 

and make up to 100 cc. Treat with 2 drops of freshly prepared, colorless ammo- 
nium sulphid solution, mix and compare in a colorimeter with standard solutions, 
prepared by adding measured amounts of the standard lead solution to 50 cc. of 
the lead-free tartrate solution, diluting to 100 cc. and treating with 2 drops of 
freshly prepared colorless ammonium sulphid solution. 

The final comparison should be made with a standard containing approximately 
the same amount of lead, and the addition of ammonium sulphid solution should be 
made to the standards and the solution of the sample at the same time, as the colors 
change on standing. 

31 Method II.— Tentative. 

(Applicable to alum or phosphate baking powders or their ingredients.) 

Weigh 100 grams of the sample into a 1.3 liter beaker and add an excess of hy- 
drochloric acid (1 to 3) in small portions, keeping down excessive frothing with a 
little ether. Heat the mixture on a steam bath until the starch is hydrolyzed and 
the solution is quite limpid. Cool and add 200 cc. of 50% lead-free ammonium 
citrate solution. Place the beaker in a bath of cold water and add carefully ammo- 
nium hydroxid solution, in small portions wath constant stirring, until the mixture 
is alkaline. If a precipitate forms, add sufficient ammonium citrate solution to 
dissolve it. Then add 15 cc. of saturated mercuric chlorid solution, dilute the 
mixture to about 1200 cc, saturate with hydrogen sulphid and allow to stand 
until the precipitate has settled (15-20 minutes). Filter and wash the precipitate 
with hydrogen sulphid water. Place the paper and precipitate in a small casserole, 
add 10 cc. of concentrated nitric acid and 2 cc. of concentrated sulphuric acid and 
heat on a hot plate until the mixed acids have been slowly driven off. Heat the 
residue in a muffle at low redness until the mercury salts have volatilized. Cool 
the casserole and leach the residue several times with 25% ammonium acetate solu- 
tion, made slightly alkaline with ammonium hydroxid, pass the leachings through 
a small filter into a beaker and finally wash the residue and filter paper with a 
little hot water. Acidify the combined filtrate and washings wdth acetic acid, add 
an excess of potassium dichromate solution and allow to stand overnight. Filter 
on a tared Gooch, wash with water, dry for 30 minutes at 125°-150°C., cool and 
weigh as lead chromate. Calculate the weight of metallic lead. Conduct a blank 
determination upon all the reagents and correct the result accordingly. 

32 Method 1 1 1. —Tentative. 

(Applicable to alum or phosphate baking powders or their ingredients.) 

Transfer 200 grams of the sample to a 3 liter Jena flask, add 300 cc. of concen- 
trated nitric acid in small portions, shake thoroughly after each addition and 
heat the mixture slowly, shaking repeatedly. When brown fumes begin to appear 
at the mouth of the flask, discontinue heating and insert a stemless funnel in the 
neck of the flask. As soon as the action has moderated, place the flask on an 
asbestos gauze over a small Bunsen flame. When the action becomes weak, add 
slowly 90 cc. of concentrated sulphuric acid and continue heating until the fumes 
disappear. Then add 25 cc. of concentrated nitric acid from time to time with con- 
tinued heating until all the starch is completely oxidized. Usually 3-4 additions 
of 25 cc. portions of nitric acid suflfice. Finally expel the nitric acid as completely 
as possible. Cool, add 400 cc. of water, shake and allow to settle. The soluble sul- 
phates of sodium, potassium, aluminium, iron, etc., go into solution, while calcium 
sulphate and most of the lead sulphate will be precipitated. Filter through an 18 



XXVIII] BAKING POWDERS 349 

cm. folded filter into a liter Erlenmeyer flask, rinse the 3 liter flask 2-3 times with 
small portions of water and pour the rinsings through the filter. Reserve the fil- 
trate for the recovery of dissolved lead salts. Open the filter, containing the pre- 
cipitate, over a 600 cc. beaker and wash the precipitate into it. Then transfer the 
contents of the beaker to a 2 liter Erlenmeyer flask together with whatever pre- 
cipitate remains in the 3 liter flask. Dilute the contents of the flask so as to nearly 
fill the latter, stir thoroughly to dissolve the calcium sulphate, add 20 cc. of strong 
acetic acid and saturate the liquid thoroughly with hydrogen sulphid. Stopper 
the flask and set aside until the precipitate settles. Siphon off the supernatant 
liquid. When much calcium sulphate is present, one such treatment is not suffi- 
cient to dissolve all of it. In this case refill the flask with water, again acidify, 
saturate with hydrogen sulphid and allow to stand till the calcium sulphate is 
practically all dissolved and the residue of sulphids is dark colored. Solution may 
be hastened by the addition of lead-free sodium acetate to the water (50-75 grams 
to each 2 liters). 

Treat the liquid containing the soluble sulphates separately to recover the trace 
of lead which it may contain. Partially neutralize with ammonium hydroxid solu- 
tion just short of the point of producing a permanent precipitate of aluminium 
phosphate, saturate with hydrogen sulphid and allow the pi-ecipitate to settle. 
Some iron sulphid also will usually be precipitated. The sulphid precipitations 
should be made in very slightly acid solutions, otherwise lead sulphid will not be 
precipitated completely. Siphon off the supernatant liquid, transfer the precipi- 
tate to an 11 cm. filter and wash with hydrogen sulphid water. Transfer the first 
precipitate remaining in the 2 liter flask to a second 11 cm. filter and treat in the 
same way. Place the 2 filters with their contents in a 200 cc. Erlenmeyer flask, 
add 10 cc. of concentrated nitric acid and 5 cc. of concentrated sulphuric acid, 
insert a stemless funnel in the neck and heat to completely oxidize the material. 
When the nitric acid has all been expelled and the residue darkens, add more nitric 
acid until no such darkening occurs. Finally heat the residue till fumes of sulphur 
trioxid are given off, cool and add 15 cc. of water. Filter through a 7 cm. filter, 
rinse, then wash the filter twice with small portions of dilute sulphuric acid and 
finally with a little water. Place a clean 150 cc. beaker under the filter, dissolve 
the precipitate in 15-25 cc. of ammonium acetate solution [1 part of 99% acetic 
acid, 1 of water and 1 of ammonium hydroxid (sp. gr. 0.90); made neutral to lit- 
mus paper] and wash thoroughly with water. 

Acidify the filtrate and washings with acetic acid, add an excess of potassium 
dichromate solution, heat on a steam bath and allow to cool and settle. Filter on 
a tared Gooch prepared with a thick layer of asbestos which has been previously 
dried at 125°C., wash with water, dry at about 125°C. and weigh as lead chromate. 

33 Method IV. — Tentative. 

(Applicable in the absence of alum and phosphates.) 

Weigh 100 grams of the sample into a liter beaker and add an excess of hydro- 
chloric acid (1 to 3) in small portions, keeping down excessive frothing with a little 
ether. Heat the mixture on a steam bath until the starch is hydrolyzed and the 
solution is quite limpid. Cool, add ammonium hydroxid solution until distinctly 
alkaline, dilute to about 800-900 cc. and saturate with hydrogen sulphid. Allow 
the mixture to stand for 3-4 hours or until the precipitate has settled, filter on a 
12.5 cm. close-textured paper and wash the precipitate several times with hydrogen 
sulphid water. Place the filter paper and precipitate in a 100 cc. Erlenmeyer flask, 
add 5 cc. of concentrated sulphuric acid and 5 cc. of concentrated nitric acid and 



METHODS OF ANALYSIS 

heat on a hot plate, with occasional additions, of small portions of concentrated 
nitric acid, until the mixture no longer blackens when evaporated to the point at 
which white fumes of sulphur trioxid appear. Cool, dilute with 20 cc. of water, 
warm until the ferric sulphate goes into solution, cool and then add 40 cc. of 95% 
alcohol by volume. Allow to stand overnight, filter on a Gooch and wash with 
95% alcohol. Dissolve the lead sulphate remaining on the filter by washing with 
20 cc. of 25% ammonium acetate solution, rendered slightly alkaline with ammo- 
nium hydroxid, collect the filtrate in a small beaker, passing it through the filter 
3-4 times. Finally wash the filter with hot water, acidify the combined filtrate 
and washings with acetic acid, add an excess of potassium dichromate solution and 
allow to stand overnight. Filter on a small, tared Gooch, wash, dry for 30 minutes 
at 125°-150°C. and weigh as lead chromate. Calculate the metallic lead. 

34 ARSENIC— TENTATIVE. 

Introduce 5 grams of the sample directly into the generator described under 
XII, 2 (Fig. 7), add 10 cc. of water, a little at a time to prevent foaming over, 
and then 15 cc. of concentrated, arsenic-free hydrochloric acid, introducing it drop 
bj' drop until foaming ceases. Heat on a steam bath until a drop of the mixture, 
when diluted and treated with iodin solution, shows no blue color. Then dilute to 
about 30 cc. with water, add 4 cc. of potassium iodid solution and continue from 
this point as directed under XII, 4, beginning with "Heat to about 90°C.", except 
that the blank and the standards for comparison are made by the use of the arsenic- 
free hydrochloric acid of the same concentration as that used in the determination. 

BIBLIOGRAPHY. 

1 J. Am. Chem. Soc, 1899, 21: 396. 

2 Ibid., 1896, 18:1. 

s Conn. Agr. Exp. Sta. Rept., 1900. (11), p. 169. 

* Inland Revenue Dept., Canada, Bull. 68, p. 31. 

^ Catlin. Baking Powders: A Treatise on Their Character, Method for Deter- 
mination of Their Values, etc. p. 20. 

6 Ann. chim. anal., 1899, 4: 263. 

•> Conn. Agr. Exp. Sta. Rept., 1900, (II), p. ISO. 

» Ibid., p. 174. 

8 Rept. Mass. State Board of Health, 1899, p. 638. 
1° Conn. Agr. Exp. Sta. Rept., 1900, (II), p. 178. 

" U. S. Bur. Chem. Bull. 13 (V), p. 596; Conn. Agr. Exp. Sta. Rept., 1900, (II), 
p. 179. 
12 J. Assoc. Official Agr. Chemists, 1915, 1: 249. 



XXIX. DRUGS. 

Caffein and Acetanilid in Mixtures. 

t PREPARATION OF SAMPLE AND SOLUTION.— TENTATIVE. 

(a) If the sample is already in powder form, rub thoroughly in a mortar and 
keep in a tightly corked tube or flask. Powders in paper, cachet or capsule con- 
tainers are frequently of such fineness as to require little further trituration except 
to produce a uniform product. On a tared 5.5 cm. filter weigh 0.3-0.5 gram of the 
sample or, if preferred, an amount equal to, or a multiple of, the average unit dose 
(previously ascertained by weighing collectively 20 or more such doses), wash with 
successive 5-10 cc. portions of the chloroform (30-50 cc. are usually sufficient) until 
the extraction is complete as indicated by the absence of any residue after evapora- 
tion of a small portion of the last washing. Collect the solution in a 200 cc. Erlen- 
meyer flask, connect the flask with a condenser by means of a cylindrical Kjeldahl 
connecting bulb^ and distil until the volume is reduced to about 10 cc. 

(b) If the caffein is present in the citrated form, or the composition of the mix- 
ture precludes complete extraction as directed in (a), weigh out the desired amount, 
transfer to a Squibb separatory funnel, add 50 cc. of the chloroform and 20 cc. of 
water, shake vigorously and, after clearing, draw off the lower layer through a 
small, dry filter into a 200 cc. Erlenmeyer flask. In the case of coated tablets and 
pills, ascertain their average weight, powder in a mortar and weigh out for each 
determination an amount equivalent to one or more tablets or pills. Repeat the 
extraction twice, using 50 cc. portions of the chloroform for each extraction. Dis- 
til the combined chloroform extracts to about 10 cc. 

(C) In the case of dilute alcoholic solutions, evaporate a measured quantity on 
a steam bath until most of the alcohol has been expelled, or take an aliquot of 
the residue from an alcohol determination; transfer to a separatory funnel by pour- 
ing and rinsing with a minimum of water so that the final volume does not greatly 
exceed 20 cc, and then, in order to avoid any loss of acetanilid by hydrolysis during 
evaporation, add a little solid sodium bicarbonate and a drop of acetic anhydrid. 
(Should the preparation contain alkaloids, acidify with a few drops of dilute sul- 
phuric acid immediately after acetylization to retain such basic material in solu- 
tion.) Add 50 cc. of the chloroform, shake vigorously and, after clearing, draw off 
the chloroform layer through a filter into a 200 cc. Erlenmeyer flask. Repeat the 
extraction twice, using 50 cc. portions of the chloroform for each extraction, and 
distil the combined chloroform washings to a volume of about 10 cc. 

CAFFEIN AND ACETANILID.— TENTATIVE. 

2 REAGENTS. 

(a) Standard hromid-hr ornate solution. — Dissolve 50 grams of potassium hydroxid 
in a small quantity of water, add a slight excess of bromin, dilute with water to dis- 
solve any separated salts, boil to expel excess of bromin and dilute to 1 liter. Stand- 
ardize the solution against recrystallized acetanilid and adjust the solution so that 
1 cc. is equivalent to 5 or 10 mg. of acetanilid as desired. 

(b) Chloroform. — Redistilled and residue-free. All corks used in the distillation 
should be treated previously with chloroform. 

351 



352 METHODS OF ANALYSIS [Chap. 

(C) Wagner's reagent. — Dissolve 2 grams of iodin and 6 of potassium iodid in a 
minimum amount of water and dilute to 100 cc. 

3 CAFFEIN.— TENTATIVE, 

Treat the chloroform extract, obtained in 1 , with 10 cc. of sulphuric acid (1 to 
10) and digest on a steam bath until the contents of the flask are reduced to 5 cc. 
Add 10 cc. of water and continue the digestion until the liquid is again reduced to 
5 cc, then cool and transfer to a separatory funnel with a minimum of water, so 
that the final volume does not greatly exceed 20 cc. Add 50 cc. of the chloroform, 
extract in the usual way and, after clearing, withdraw the lower layer through a 
small, dry filter into a 200 cc. Erlenmeyer flask. Repeat the extraction with two 
50 cc. portions of the chloroform. On the completion of the third extraction, 
distil the combined extracts down to about 10 cc, finally transferring the residual 
liquid, bj' washing with chloroform, to a tared beaker or crystallizing dish. Allow 
the solution to evaporate spontaneously, or by gentle heat and an air blast, to 
apparent dryness. Cool and allow to stand until the weight becomes constant. 

Chloroform extracts in addition to caffein and acetanilid certain oils, fats, waxes, 
resins, pigments and other substances from those preparations which contain pow- 
dered cinnamon, celery seed, ginger or other vegetable products. These appear either 
in suspension or solution after the caffein-acetanilid mixture has been digested and 
contaminate the caffein. Remove any suspended impurities by filtering through 
a small, moistened filter immediately after hydrolysis and prior to extraction with 
chloroform. Should the recovered caffein be deeply colored or contaminated with 
foreign matter, purify it as follows: Dissolve in very dilute sulphuric acid (about 
5 cc of N/5 acid for every 100 mg. of caffein), filter, if necessary, through a mois- 
tened filter, add 15-20 cc. of Wagner's reagent, sufficient at least to distinctly color 
the supernatant liquid, stir and allow to stand an hour, preferably in a refrigerator. 
Filter and wash the periodid with a few cc of iodin solution, transfer both filter and 
precipitate to a separatory funnel, using not more than 20 cc. of water, decolorize 
with a crystal of sodium thiosulphate, then extract with three 50 cc. portions of 
chloroform and proceed as directed above. 

4 ACETANILID.— TENTATIVE. 

Transfer the solution of anilin sulphate, remaining in the separatory funnel 
in 3, to the Erlenmeyer flask used in effecting hydrolysis, then heat 10 minutes on 
a steam bath to expel all traces of chloroform. Wash the filter, used in the pre- 
ceding operation to dry the chloroform solution of caffein, with 5 cc. of water, 
adding the latter to the main solution of anilin sulphate. Add 10 cc. of concen- 
trated hydrochloric acid, then run in the standard bromid-bromate solution until 
a faint yellow coloration remains, rotating the flask sufficiently to agglomerate the 
precipitated tribromanilin. Calculate the quantity of acetanilid from the number 
of cc. required to complete the precipitation. 

Caffein and acetanilid are the 2 principal ingredients of the preparation known 
as "acetanilid compound", a further constituent being sodium bicarbonate. The 
latter appears as the chloroform-insoluble residue and may be determined by ti- 
trating such residue, or one obtained by titrating a portion of the original mixture, 
with standard acid, using congo red as an indicator. The bicarbonate may also 
be determined by igniting the original sample, or the chloroform-insoluble residue, 
with sulphuric acid and weighing the resulting sodium sulphate. 

Should the "acetanilid compound" be combined with sodium bromid, the latter, 
in the absence of other halides, may be determined volumetrically by the Volhard 
method [III, 15]. 



XXIX] DRUGS 353 

Caffein and Acetphenetidin CPhenacetin) in Mixtures. 

5 preparation of sample and solution.— tentative. 

In the case of preparations containing acetphenetidin instead of acetanilid, but 
otherwise identical, make the gross separation of the caffein-acetphenetidin mix- 
ture as directed under 1 . 

6 caffein.— tentative. 

Treat the chloroform extract, obtained as directed under 1, with 10 cc. of sul- 
phuric acid (1 to 10) and digest on a steam bath until the liquid is reduced to about 
5 cc. Dilute with 10 cc. of water and continue the digestion until the volume is 
again reduced to 5 cc, then add 10 cc. of water and continue heating until the 
residual liquid amounts to 8-10 cc. If, during the digestion, particles of acet- 
phenetidin remain on the sides of the flask rinse them into the solution with a few 
drops of chloroform. 

Great care must also be given to the degree of evaporation. Should the aqueous- 
acid solution and suspension of caffein-acetphenetidin be concentrated far beyond 
the limits indicated, more or less phenetidin sulphonate is likely to be formed, 
which later resists acetylization and conversion to acetphenetidin. 

Cool and transfer with water to a separatory funnel, so that the final volume does 
not greatly exceed 20 cc. Then proceed as directed under 3. 

7 acetphenetidin.— tentative. 

Wash the filter, used to dry the chloroform in 6, with 5 cc. of water, receiving the 
te r in the separatory funnel containing the solution of phenetidin sulphate. 
Treat with successive small portions of solid sodium bicarbonate until, after com- 
plete neutralization of free acid, an excess of the former remains at the bottom of the 
mixture. Add 50 cc. of chloroform and for every 0.10 gram of acetphenetidin, known 
or believed to have been present, 5 drops of acetic anhydrid; shake vigorously, allow 
to clear, then withdraw the chloroform into a second separator}^ funnel containing 
5 cc. of water. Shake this mixture and, after clearing, pass the solvent through a 
small, dry filter into a 200 cc. Erlenmeyer flask. Distil over about 40 cc. of the 
chloroform, make up the distillate to 50 cc. with chloroform, add this to the mate- 
rial in the first separatory funnel and extract again. Withdraw the chloroform 
layer to the second separatory funnel, wash and distil about 50 cc. (for use in the 
final extraction). Distil the chloroform down to about 10 cc, transfer with sufficient 
fresh solvent to a tared 50 cc beaker or crystallizing dish, evaporate on the steam 
bath to apparent dryness, finally removing any considerable excess of acetic anhy- 
drid by repeated additions of 1 cc of chloroform and a drop of alcohol. The re- 
formed acetphenetidin should finally appear as a whitish, crystalline mass with 
a faint, acetous odor which disappears completely on standing some hours in the 
open, or in a vacuum desiccator over lime. Weigh from time to time until the 
final weight differs from the preceding by not more than 0.5 mg. 

Caffein and Antipyrin in Mixtures^. 

8 preparation of sample and solution.— tentative. 

(a) Extract a weighed portion of the finely powdered sample on a filter with 
chloroform to separate the caffein and antipyrin from the usual excipients of tab- 
let and pill combinations. Distil off the greater part of the chloroform and evap- 
orate the remainder on the steam bath. 



354 METHODS OF ANALYSIS [Chap. 



(b) In the case of alcoholic preparations, remove the alcohol from a measured 
amount of the sample by heating on a steam bath. Extract the residue with three 
50 cc. portions of chloroform in a separatory funnel. Distil off the- greater por- 
tion of the chloroform and evaporate the remainder on a steam bath. 

9 ANTIPYRIN.-TENTATIVE. 

Transfer the residue, obtained in 8, which should weigh about 0.25 gram, to a 
150 cc. separatory funnel by means of two 5 cc. portions of alcohol-free chloroform, 
followed by 10 cc. of water. Add 1 gram of sodium bicarbonate and 10-15 cc. of 
N/5 iodin (or double the quantity of N/10 iodin), adding the latter in small por- 
tions and shaking the mixture vigorously after each addition. The iodin should 
then be in excess of that required to convert all the antipyrin into the mono-iod 
derivative. If not, add a little more and shake the mixture again. Remove the 
free iodin with a small crystal of sodium thiosulphate, add 15 cc. of chloroform, 
shaking vigorously for 1 minute. After clearing, draw off the chloroform solution 
into a second separatory funnel, wash with 5 cc. of water, filter through a small, 
dry filter into a tared 50 cc. beaker and evaporate to apparent dryness on the steam 
bath, using an air blast. Repeat the extraction with two (three, if N/10 iodin is 
used) 25 cc. portions of chloroform, wash, filter and evaporate each portion as 
above. Dry the nearly colorless, crystalline residue of caffein and iodantipyrin 30 
minutes at 105°C., cool and weigh. Designate this weight as "a". 

Dissolve the composite residue in 5 cc. of glacial acetic acid, add 10 cc. of 
saturated sulphur dioxid solution, then transfer with hot water to a 400-500 
cc. beaker until the final volume amounts to about 200 cc. Add sufficient silver 
nitrate solution to precipitate all the iodin (about 0.3 gram of silver nitrate) ; then 
a few drops of nitric acid, heat nearly to boiling and stir to agglomerate the silver 
iodid. Add 15 cc. of concentrated nitric acid, cover the beaker with a watch glass 
and boil gently for 5 minutes. Filter by decantation through a tared Gooch, wash 
the precipitate once with a little alcohol, then with two 100 cc. portions of boiling 
water and finally transfer the iodid to the crucible. Wash several times with hot 
water and again with alcohol to remove traces of organic matter, dry 30 minutes 
in an air bath at 110°C., cool and weigh. The weight of silver iodid multiplied by 
0.8012 gives the weight of antipyrin. 

10 CAFFEIN.— TENTATIVE. 

Calculate the quantity of caffein by multiplying the weight of silver iodid by 
1.3374 and subtracting the product from the weight "a" above. 

In the analysis of a mixture containing caffein, antipyrin, acetanilid and sodium 
salicylate, the following steps are essential in effecting a separation: (1) Extraction 
of caffein, acetanilid and antipyrin with chloroform from the aqueous soda solution; 
(2) Hydrolysis with sulphuric acid of the 3 substances thus separated preliminary 
to the determination of caffein and antipyrin as directed in 9 and 10. 

Acetanilid and Acetphenetidin (Phenacetinj in Mixtures', 
acetphe netidi n.-te ntative. 

11 REAGENTS. 

(a) Purified iodin. — Dissolve 2 parts of resublimed iodin and 1 of potassium iodid 
in 1 of water, pour the clear solution into a large volume of water, filter and wash 
the finely precipitated iodin several times on a porous plate with water. Dry in 
the air and finally in a desiccator over sulphuric acid where it is kept in a glass- 
stoppered weighing bottle. 



XXIX] DRUGS 355 

(b) Standard sodium thiosulphate solution. — Dissolve 30 grams of crystallized 
sodium thiosulphate in water and dilute to 1 liter. Standardize this solution against 
the purified iodin as follows: Weigh out about 0.3 gram of the purified iodin in a 
small, glass capsule (about ^ inch high and f inch diameter), provided with a closely 
fitting glass cap or stopper, and place the capsule in a 200 cc. Erlenmeyer flask con- 
taining 0.5 gram of potassium iodid dissolved in 10 cc. of water. After complete 
solution, titrate with the sodium thiosulphate solution, using 1 or 2 drops of starch 
solution as an indicator. 

(C) Standard iodin solution. — Dissolve 40 grams of potassium iodid in the least 
possible quantity of water, add 30 grams of the purified iodin and, after solution, 
dilute to 1 liter. Standardize 25 cc. of this solution against the standard sodium 
thiosulphate solution. 

12 DETERMINATION. 

(1) Place 0.2 gram of the acetphenetidin-acetanilid mixture in a 50 cc. lipped 
Erlenmeyer flask, add 2 cc. of glacial acetic acid, heat gently over a wire gauze to 
complete solution and dilute with 40 cc. of water, previously warmed to 70°C. 
Transfer the clear liquid with two 10 cc. portions of warm (40°C.) water to a glass- 
stoppered, 100 cc. graduated flask containing 25 cc. of the standard iodin solution 
warmed to 40°C. Stopper, mix thoroughly, then add 3 cc. of concentrated hydro- 
chloric acid, continue shaking until crystallization begins and then set aside to 
cool. If the ratio of acetphenetidin to acetanilid is equal to or greater than unity, 
crystalline scales will form almost immediately on the addition of acid. As the 
proportion of acetanilid increases, however, the periodid tends to remain in the liquid 
state. In such cases, gentle agitation or rotation of the flask in water, warmed 
not to exceed 40°C., hastens the formation of crystals. When the contents of the 
flask are at room temperature, fill with water to within 2-3 cc. of the mark, mix 
thoroughly and allow to stand overnight. Fill to the mark with water, mix thor- 
oughly, allow to stand 30 minutes, filter through a 5.5 cm. dry, closely fitted filter 
into a 50 cc. graduated flask, rejecting, however, about 15 cc. of the first runnings 
but reserving them for the recovery of acetanilid. Transfer the 50 cc. aliquot to a 
200 cc. Erlenmeyer flask and titrate with the standard sodium thiosulphate solution. 
Calculate the amount of acetphenetidin from the following formula: 

Acetphenetidin = I (0.0896 X N) in which 

0.0896 = the quantity of acetphenetidin contained in 1 cc. of a normal 
solution of this substance; 
N = the normality of the standard sodium thiosulphate solution 

employed; and 
I = the number of cc. of the standard sodium thiosulphate solu- 
tion corresponding to the iodin combined with the acet- 
phenetidin. 

The formula of the precipitated periodid,. which constitutes the basis for the above 
determination, is (C2H60.C6H4NH.COCH3)2HI.l4. 

(2) The gravimetric determination of acetphenetidin may, if desired, be effected 
as follows : Filter off the periodid, preferably by suction, wash with 10-15 cc. of the 
standard iodin solution, then transfer together with the filter to a separatory funnel, 
using not over 50 cc. of water. Remove both free and added iodin with a fe^y small 
crystals of sodium sulphite and extract the liquid with three 50 cc. portions of 
chloroform, washing each portion subsequently into a second separatory funnel with 
5 cc. of water. After washing and clearing, filter the chloroform solution through 



356 METHODS OF ANALYSIS [Chap. 

a dry 5.5 cm. filter into a 200 cc. Erlenmeyer flask, distil off most of the chloro- 
form, transfer the residual solution (5-10 cc), by means of a little chloroform, to 
a small, tared beaker or crystallizing dish, evaporate to dryness on a steam bath, 
cool and weigh. 

For the identification of acetphenetidin, either alone or in admixture with acet- 
anilid, the following test will be found of value^: To 1-2 mg. of the sample in a test 
tube add a drop of acetic acid, 0.5 cc. of water and 1 cc. of N/10 iodin, warm the 
mixture to about 40°C., then add a drop of concentrated hydrochloric acid. If 
acetphenetidin alone is present, its periodid separates almost immediately in the 
form of reddish brown leaflets or needle-like crystals. If the sample consists largely 
of acetanilid, the separation takes place on cooling and shaking the liquid. In the 
presence of considerable acetanilid, the periodid first separates as minute, oily 
globules, which, on vigorous shaking, gradually become crystalline. This test is so 
delicate that as little as 0.5 mg. of acetphenetidin may, if alone, be detected in 
the form of its characteristic periodid. 

1 3 ACETANILID.— TENTATIVE. 

(1) If the combined weight of the acetphenetidin-acetanilid mixture is known, 
determine that of the latter ingredient by difference; or, (2) Determine it directly 
from a second aliquot of the filtrate from the acetphenetidin periodid in 1 2 as follows : 

Pipette 25-30 cc. of the clear liquid into a separatory funnel, decolorize with 
solid sodium sulphite and solid sodium bicarbonate in slight excess, add 1 or 2 drops 
of acetic anhydrid, then extract with three 60 cc. portions of chloroform, passing 
the chloroform solution, when cleared, through a small, dry filter into a 200 cc. 
Erlenmeyer flask, and distil the chloroform, by the aid of gentle heat, to about 20 
cc. Add 10 cc. of sulphuric acid (1 to 10) and digest on a steam bath until the resi- 
due has been reduced one half, add 20 cc. of water and continue the digestion for 
an hour; then add a second 20 cc. portion of water and 10 cc. of concentrated hydro- 
chloric acid, titrate very slowly, drop by drop, with the standard bromid-bromate solu- 
tion, 2 (a), until a faint yellow color remains. While adding this reagent, rotate 
the flask sufficiently to agglomerate the precipitated tribromanilin. Calculate the 
amount of acetanilid present. 

If the preparation contains caffein or antipyrin or both in addition to acet- 
anilid and acetphenetidin, proceed as follows: (1) Digest the mixture by heating 
with dilute sulphuric acid to convert acetphenetidin and acetanilid to phenetidin 
and anilin sulphates, respectively; (2) Separate the caffein and antipyrin by ex- 
traction with chloroform; (3) Re-form acetphenetidin and acetanilid by treat- 
ing the solution of the corresponding sulphates with solid sodium bicarbonate in 
slight excess, then add a few drops of acetic anhydrid and extract with chloroform*. 

Acetphenetidin CPhenacetin) and Salol in Mixtures^ 
acetphenetidin. 

14 Acid Hydrolysis Method. — Tentative. 

Weigh out on a tared 5.5 cm. filter an amount of the sample equal to, or a mul- 
tiple of, the average weight of a unit dose and wash with sufficient successive, small 
portions of chloroform to extract completely all acetphenetidin and salol present 
in the mixture (about 40 cc). Collect the solution in a tared, 100 cc. beaker and 
evaporate on a warm plate (50°-60°C.) to apparent dryness, using an air blast. 
Let stand 24 hours at room temperature to practically constant weight, then trans- 
fer the crystalline residue, by means of chloroform, to a 50 cc. lipped Erlenmeyer 
flask, evaporate the solvent by means of an air blast and gentle heat, add 10 cc. 



XXIX] DRUGS 357 

of sulphuric acid (1 to 10) and evaporate on the steam bath until the volume is re- 
duced one half. Add 10 cc. of water and continue the digestion as before, then add 
a second 10 cc. of water and evaporate to 5 cc. Transfer the residue with about 
20 cc. of water to a small separatory funnel and extract with 15, 10 and 5 cc. of 
chloroform, washing each extract with 5 cc. of water in a second separatory funnel 
to recover traces of phenetidin sulphate possibly dissolved by the chloroform, 
finally rejecting the latter since it contains all the salol not previously eliminated 
during the digestion. 

Add the wash water in the second separatory funnel to the solution of phenetidin 
sulphate in the first separatory funnel and proceed as directed under 7, beginning 
with "Treat with successive small portions of solid sodium bicarbonate". 

15 Alkaline Hydrolysis Method. — Tentative. 

On a small, tared filter weigh out an amount of the sample to contain not more 
than 0.10 gram of salol, exhaust with chloroform as directed in 14, collect the sol- 
vent in a small, lipped Erlenmeyer flask and evaporate the chloroform by means of 
an air blast without heat. Add 10 cc. of 2.5% sodium hydroxid solution and heat 5 
minutes on a steam bath. Cool quickly to room temperature in running water to 
prevent partial hydrolysis of the acetphenetidin. Transfer the liquid to a separa- 
tory funnel with a minimum of water, then rinse out the flask with the first 20 cc. 
portion of chloroform used in the extraction. Extract the alkaline solution with 
three 20 cc. portions of chloroform, wash each portion in a second separatory funnel 
with 5 cc. of water and pass the solution through a small, dry filter into a 200 cc. 
Erlenmeyer flask. Designate the combined alkaline solution and washings as A. 
Distil the combined chloroform extracts to about 5 cc. Transfer by means of a 
little chloroform to a small, tared beaker or crystallizing dish, evaporate on a steam 
bath with the aid of an air blast, cool and weigh the residual acetphenetidin at 
intervals until the weigBt becomes constant. 

SALOL. 

16 Acid Hydrolysis Method. — Tentative. 

Subtract the weight of acetphenetidin, as determined in 14, from the combined 
weight of the 2 ingredients determined in 1 4, to obtain the weight of salol. 

1 7 . Alkaline Hydrolysis Method. — Tentative. 

Place the combined alkaline solutions, A, under 1 5, in a 500 cc. glass-stoppered 
bottle, dilute with water to about 200 cc, run in from a burette an excess (about 
45 cc.) of N/7 potassium bromid-bromate, add 10 cc. of concentrated hydrochloric 
acid and shake 1 minute, then at intervals for 30 minutes. Add 10 cc. of 15% potas- 
sium iodid solution and shake at intervals for 15 minutes. Titrate the free iodin 
with standard sodium thiosulphate solution (preferably N/7), previously standard- 
ized against the N/7 bromid-bromate solution. One cc. of N/7 potassium bromid- 
bromate is equivalent to 2.55 mg. of salol. From the number of cc. of the N/7 
bromid-bromate solution used, calculate the amount of salol on the basis of 12 atoms 
of bromin to 1 molecule of salol. 

ACETANILID AND SODIUM SALICYLATE IN MIXTURES. 
18 PREPARATION OF SAMPLE AND SOLUTION.— TENTATIVE. 

Weigh an amount of the powdered sample equal to, or a multiple of, an average 
unit dose, transfer to a separatory funnel containing 10 cc. of water and, for every 
unit dose, add 0.10 gram of solid sodium bicarbonate. In the case of coated tablets 



358 METHODS OF ANALYSIS [Chap. 

and pills, ascertain their average weight, powder in a mortar and weigh out an 
amount of the powder equivalent to one or more tablets or pills for each determina- 
tion prior to treatment in the scparatory funnel. In the examination of alcoholic 
preparations, distil off the alcohol from a measured volume on a steam bath, 
transfer to a scparatory funnel with a minimum of water and add sufficient solid 
sodium bicarbonate (0.5 to 1.0 gram). 

19 ACETANILID.— TENTATIVE. 

Extract the alkaline solution, obtained under 18, with three 50 cc. portions of 
chloroform, wash each portion with 5 cc. of water in a second scparatory funnel 
and collect the solvent, without previous drying, in a 200 cc. Erlenmeyer flask. 
Designate the aqueous solution as A. Distil off the chloroform very gently to 
about 5 cc, add 10 cc. of dilute sulphuric acid and completely hydrolyze on the 
steam bath. Proceed from this point as directed in 4. 

20 SODIUM SALICYLATE— TENTATIVE. 

Acidify the aqueous solution of sodium salicylate. A, under 19, with a few drops 
of concentrated hydrochloric acid and extract with sufficient (3-5) 25 cc. portions 
of chloroform to exhaust the salicylic acid present in the mixture. Treat each por- 
tion in a second scparatory funnel with 20 cc. of water, containing 1 gram of 
anhydrous sodium carbonate for every 100 mg. of salicylic acid. Shake vigorously 
and, after clearing, wash each portion again in a second scparatory funnel with 5 cc. 
of water, then add the washings to the main aqueous soda solution of sodiimi 
salicylate. Dilute to a known volume, transfer an aliquot, representing about 100 
mg. of salicylic acid, to a 200 cc. Erlenmeyer flask, make up to 100 cc, heat nearly 
to boiling, then run in from a burette 25-40 cc. of strong (about N/5) iodin solu- 
tion, sufficient to insure an excess during digestion and digest for an hour on a steam 
bath. Remove the free iodin with a few drops of sodium thiosulphate solution, 
decant the clear liquid through a tared Gooch, retaining most of the precipitate, 
tetraiodophenylenquinon (C6H2l20)2, in the flask. To the latter add 50 cc. of 
boiling water, digest 10 minutes on the steam bath, then filter, wash gradually 
all the precipitate into a Gooch, using for this purpose and the final washing 
about 200 cc. of hot water. Dry to constant weight in an air bath at 100°C. Mul- 
tiply the weight of the precipitate by 0.4654 to obtain the quantity of sodium 
salicylate present in the aliquot taken. 

Should the mixture contain caffein or antipyrin, or both, these substances will 
appear with the acetanilid in the first chloroform extract and may be determined 
as directed in the closely set type following 1 0. Should the acetanilid be replaced by 
acetphenetidin in the mixture, the general procedure would not be materially altered, 
the acetphenetidin being weighed directly after recovery from its washed chloro- 
form solution as separated from the sodium salicylate. If, instead of sodium sal- 
icylate, the mixture contains the free acid or its ammonium salt, add a larger quan- 
tity of sodium bicarbonate prior to extraction with chloroform to insure the fixation 
of salicylic acid. 

In the analysis of a mixture of caffein, acetanilid, sodium salicylate and codein 
sulphate, the following procedure is recommended: (1) Extraction of caffein, acet- 
anilid and salicylic acid from the acidified solution; (2) Washing the chloroform 
solution with aqueous soda solution for the recovery of salicylic acid, preliminary 
to its treatment with iodin solution; (3) Separation of caffein and acetanilid as 
directed under 3 and 4; (4) .Recovery of codein from the solution of its sulphate 
after treatment with sodium bicarbonate and chloroform. 



XXIX] DRUGS 359 

Caffein, Acetanilid and Qdinin Sulphate in Mixtures. 

21 preparation of sample and solution.— tentative. 

Transfer to a separatory funnel one or more average unit doses of the powdered 
sample, add 20 cc. of water and 50 cc. of chloroform, then 10 drops of dilute sulphuric 
acid and extract in the usual way. After clearing, wash the solvent in a second 
separatory funnel with 5 cc. of water prior to transferring to a 200 cc. Erlenmeyer 
flask. Repeat the foregoing operations with two 50 cc. portions of chloroform, 
finally distilling the combined chloroform solution to about 10 cc. by gentle heat. 

22 CAFFEIN AND ACETANILID.-TENTATIVE. 

Treat the chloroform residue obtained in 21 as directed under 3 and 4. 

23 QUININ SULPHATE.— TENTATIVE. 

Combine the wash water, used in the second separatory funnel in 21, with the 
solution of quinin bisulphate, add a slight excess of solid sodium bicarbonate, ex- 
tract with three 50 cc. portions of chloroform, wash each portion with 5 cc. of water 
in a second separatory funnel and then pass through a dry filter into a 200 cc. Erlen- 
meyer flask. Distil by gentle heat to about 5 cc, evaporate on a steam bath 
to apparent dryness, dissolve the amorphous alkaloid in 5 cc. of neutral alcohol 
and titrate with N/50 hydrochloric acid to a faint red, using 2 drops of methyl red 
as an indicator. Heat on a steam bath until most of the alcohol has been expelled, 
adding, if necessary, sufficient acid to maintain the acid reaction. From the total 
number of cc. of acid employed in the titration calculate the quinin sulphate. One 
cc. of N/50 hydrochloric acid is equivalent to 8.73 mg. of quinin sulphate. 

If the mixture contains acetphenetidin in place of acetanilid, proceed as out- 
lined above, except that the separation of caffein and acetphenetidin is conducted 
as directed under 6 and 7. 

Caffein, Acetanilid and Codein Sulphate in Mixtures. 

24 preparation of sample and solution. -tentative. 
Proceed as directed under 21 . 

25 CAFFEIN AND ACETANILID.-TENTATIVE. 
Proceed as directed under 22. 

26 CODEIN SULPHATE.— TENTATIVE. 

Proceed as directed under 23 to the point indicated by the sentence "Distil by 
gentle heat to about 5 cc". Transfer the chloroform solution of codein with suffi- 
cient solvent to a small, tared beaker, evaporate to apparent dryness on a steam 
bath, add a few drops of alcohol to the amorphous residue, then a like amount of 
water and evaporate again. Finally cool and allow the usually crystalline product 
to stand until the weight becomes constant. The weight of this residue multiplied 
by 1.3144 gives the quantity of codein sulphate present. 

This result should be checked volumetrically. Dissolve the residue in 3-5 cc. of 
neutral alcohol and titrate with N/50 sulphuric acid to a faint red, using methyl 
red as an indicator. From the number of cc. of standard acid employed calculate 
the amount of codein sulphate. One cc. of N/50 sulphuric acid is equivalent to 
7.87 mg. of codein sulphate. The quantity of codein sulphate as found by weight 
will usually be slightly greater than that determined by titration. 



360 METHODS OF ANALYSIS [Chap. 

Caffein, Acetanilid, Quinin Sulphate and Morphin Sulphate in Mixtures. 

27 preparation of sample and solution.— tentative. 

Transfer to a separatory funnel an amount (containing not less than one fourth 
grain of morphin) of the powdered sample equal to, or a multiple of, a unit dose, 
add 20 cc. of water and 10 drops of dilute sulphuric acid, then extract with three 
50 cc. portions of alcohol-free chloroform, wash each portion in a second separatory 
funnel with 5 cc. of water and add the combined washings to the alkaloidal solu- 
tion in the first separatory funnel. Filter the chloroform extracts through a small, 
dry filter into a 200 cc. Erlenmeyer flask and distil by gentle heat to about 10 cc. 

28 CAFFEIN AND ACETANILID.— TENTATIVE. 
Treat the chloroform residue as directed under 3 and 4. 

29 QUININ SULPHATE.— TENTATIVE. 

Add to the solution of quinin and morphin sulphates, obtained in 27, 4-5 cc. of 
sodium hydroxid solution (1 to 10) and extract with four 40 cc. portions of chloro- 
form, wash each portion with 5 cc. of water and pass the clear solvent through a 
small, dry filter into a 200 cc. Erlenmeyer fiask. Remove the solvent by gentle 
distillation and titrate the residual quinin with N/50 hydrochloric acid as directed 
under 23. 

30 MORPHIN SULPHATE.— TENTATIVE. 

Wash the filter, employed in 29, with 5 cc. of water and add to the aqueous 
alkaline solution of the alkaloid. Now add 0.5 gram of ammonium chlorid (or an 
amount slightly in excess of that required to free the morphin as well as convert 
all sodium hydroxid to sodium chiorid) and, to the resulting ammoniacal solution, 
add 45 cc. of chloroform and 5 cc. of alcohol, then extract in the usual way, washing 
the solvent in a second separatory funnel with 5 cc. of water. After clearing, pass 
the chloroform through a small, dry filter into a 200 cc. Erlenmeyer flask. Repeat 
the extraction with three 40 cc. portions of chloroform, washing and filtering as be- 
fore, finally collecting all the solvent in an Erlenmeyer flask and distilling to about 
10 cc. Transfer with chloroform to a small, tared beaker, evaporate to apparent 
dryness, add 0.5 cc. each of water and neutral alcohol, start crystallization by 
stirring with a glass rod and finally evaporate to dryness. Cool and allow to stand 
until the weight becomes constant. 

Check the weight of morphin, thus determined, by titration with N/50 sulphuric 
acid, using a drop of methyl red as an indicator. Dissolve the alkaloid in 1-2 cc. 
of warm, neutral alcohol, then add the standard acid to a faint red. Evaporate 
most of the alcohol on a steam bath, adding, if necessary, sufficient acid to main- 
tain the acid reaction. From the volume of acid used calculate the morphin sul- 
phate. One cc. of N/50 sulphuric acid is equivalent to 7.58 mg. of morphin sulphate. 

Tragacanth. 

31 volatile acidity".— tentative. 

The quantity of volatile (acetic) acidity developed in the acid hydrolysis of gum 
tragacanth {Astragalus gummifer) affords a valuable index of the purity of this com- 
modity when compared with results obtained by similar treatment of so-called 
"Indian gum" (Cochlospernum gossypium and Sierculia urens). The term "vola- 
tile acidity" expresses the number of cc. of N/10 potassium or sodium hydro.xid 
required to neutralize the volatile (acetic) acid obtained by distilling with steam 
the products of the action of boiling aqueous phosphoric acid on 1 gram of the gum. 



XXIX] DRUGS 361 

Treat 1 gram of the whole or powdered sample in a 700 cc. round-bottomed, long- 
necked flask for several hours in the cold with 100 cc. of water and 5 cc. of sirupy 
phosphoric acid until the gum is completely swollen. Boil gently for 2 hours under 
a reflux condenser. A very small amount of cellulose substance will remain undis- 
solved. Now distil the hydrolyzed product with steam, using a spray trap^ to con- 
nect the distillation flask with the condenser and continue until the distillate 
amounts to 600 cc. and the acid residue to about 20 cc. Do not concentrate too far, 
as this would scorch the non-volatile, organic decomposition products and possibly 
contaminate the distillate. Titrate the distillate with N/10 potassium hydroxid, 
using 10 drops of phenolphthalein as an indicator, finally boiling the liquid under 
examination until a faint pink color remains. Correct the result by a blank de- 
termination and express the final result in terms of the number of cc. of N/10 
alkali required, as in the above definition. 

While tragacanth yields a practically colorless solution when boiled with aqueous 
phosphoric acid, Indian gum, on the other hand, gives a pink or rose solution. This 
reaction may be used as a preliminary test for the detection of Indian gum. 

Levant Wormseed. 

32 santonin.— tentative. 

Extract 10 grams of the sample, ground to pass a 30 mesh sieve, in a Soxhlet ex- 
traction apparatus for 3 hours with chloroform. Distil off the chloroform until 
7-8 cc. remain; add 100 cc. of 5% barium hydroxid solution and heat on a steam 
bath until the odor of chloroform has disappeared. Boil 5 minutes, cool and pass 
carbon dioxid (washed through sodium bicarbonate solution to remove traces 
of acid) until saturated. Filter on a small Buchner funnel, using suction, and wash 
twice with 10 cc. of water. Heat the filtrate on a steam bath, add 5 cc. of 25% 
hydrochloric acid and warm 5 minutes. Cool until lukewarm and extract with 20, 
15 and 15 cc. of chloroform, passing the solvent through a small filter into a flask. 
Evaporate to dryness, removing the last traces of chloroform. Dissolve in 7.5 
grams (9.5 cc.) of absolute alcohol, warming gently if necessary. Then add 42.5 
cc. of water heated to 60°-70°C., stopper the flask and allow to cool. Start crystal- 
lization at this point by scratching the side of the flask with a rod or by seeding with 
a minute crystal of santonin. (Solutions containing a liberal amount of santonin, 
kept in a cool place for 24 hours, have been found in a supersaturated condition 
where this precaution was not observed.) Maintain the flask and contents at a 
temperature of 15°-17°C. for 24 hours. Filter and wash at 15°-17°C. with two 10 
cc. portions of 15% alcohol by weight. Dry the flask and filter at 100°C., dis- 
solve the santonin left in the flask and on the filter in chloroform and filter into a 
tared beaker. Wash the flask and paper thoroughly with chloroform, evaporate 
the combined filtrate and washings, dry at 100°C. to remove all traces of chloroform 
and weigh. To the weight found add 0.04 gram for the santonin dissolved in the 
dilute alcohol and multiply the total by 10 to obtain the per cent of santonin. 

Nitroglycerin in Tablets. 

33 preparation of sample.— tentative. 

(a) Crush 25 tablets under 10 cc. of anhydrous ether in a 25 cc. cylinder by 
means of a stout glass rod. Rinse the rod with a little anhydrous ether, allow 
the insoluble material to settle and decant the solution into a 50 cc. graduated 
flask. Wash the residue repeatedly with 5 cc. portions of anhydrous ether, decant 
the washings into the flask until it is filled to the mark, stopper and mix well. 
Designate this solution as A. 



362 METHODS OF ANALYSIS [Chap. 

Add 10 cc. of water to the residue, mix well and transfer the mixture to a 
small separatory funnel by means of a little water. Extract with 3 successive 
portions of 10, 5 and 5 cc. of ether. Collect the ether extracts in a 50 cc. beaker 
and designate this solution as B. 

(b) Disintegrate 25 tablets in a small beaker with 10 cc. of water, breaking 
up any lumps with a glass rod, and transfer by means of a little water to a sepa- 
ratory funnel. Rinse the beaker with 10 cc. of ether and transfer this also to the 
funnel. Shake thoroughly, draw off the aqueous layer and transfer the ether 
through a funnel, containing a little cotton, to a 50 cc. graduated flask. Repeat 
the extraction with successive portions of ether until the flask is filled to the mark, 
stopper and mix well. Designate this solution as C. 

In hand-made and soft compressed tablets, the method described under (a) is 
preferred, since the direct extraction of the dry crushed material with ether re- 
moves most of the nitroglycerin. In hard compressed tablets, the direct extraction 
is often not nearly so complete and, in such cases, the method described under (b) 
is to be preferred. 

Nitrate Method^. — Tentative. 

34 REAGENTS. 

(a) Phenoldisulphonic acid solution. — Prepare as directed under IV, 14 (a). 

(b) Standard nitrate solution. — Dissolve 0.7217 gram of potassium nitrate in 1 
liter of water. Evaporate 10 cc. of this solution just to dryness in a porcelain dish 
on a steam bath. Cool and treat the residue with 2 cc. of the phenoldisulphonic 
acid solution, rubbing with a glass rod to insure intimate contact. After 5-10 min- 
utes dilute to 250 cc. Each cc. of this solution contains 0.004 mg. of nitrogen. Add 
an excess of potassium hydroxid solution to an aliquot of this solution and dilute 
to 100 cc. (Do not use sodium or ammonium hydroxid.) It is advisable to pre- 
pare a standard of approximately the same color as the unknown. 

35 DETERMINATION. 

Place 20 cc. of the ether solution, A or C under 33, in a dried, tared 50 cc. beaker. 
Evaporate the solvent in a vacuum desiccator containing sulphuric acid. Apply 
the vacuum gradually, to prevent boiling. Allow the beaker to remain in the 
vacuum 30 minutes after the ether has evaporated. Weigh and calculate the ether 
extract per tablet. Treat the residue with 2 cc. of the phenoldisulphonic acid solu- 
tion, rotating the beaker so that the reagent comes in contact with the entire inner 
surface. After 10 minutes add water and wash into a 100 cc. flask. Dilute to the 
mark and place 10 cc, representing 1 tablet, in a 100 cc. flask, add about 50 cc. of 
water and a few drops more of 20% potassium hydroxid solution than is required to 
neutralize the acid. Dilute to the mark and compare the color with that pro- 
duced when a standard nitrate solution is similarly treated. Any convenient col- 
orimeter or Nessler tubes may be used. Multiply the nitrate nitrogen found by 
5.4 to obtain the equivalent of nitroglycerin. 

When 33 (a) is used for the preparation of the sample, a correction, deter- 
mined as directed in 37, should be made for the amount of nitroglycerin in B 
under 33, using all of B instead of an aliquot. 

Nitrite or Modified Hay Method^. — Tentative. ' 

36 REAGENTS. 

(a) Sulphanilic acid solution. — Prepare as directed under IV, 12 (b). 

(b) Alpha-napkthylamin hydrochlorid solution. — Prepare as directed under IV, 

12 (c). 



XXIX] DRUGS 363 

(C) Standard nitrite solution. — Weigh out 0.220 gram of dry silver nitrite [XV, 
18 (C)], dissolve in a small quantity of hot water and decompose with a slight ex- 
cess of sodium chlorid solution. When the solution becomes clear, dilute to 1 liter 
with nitrite-free water. Dilute 5 cc. of this solution to 1 liter with nitrite-free water. 
The second dilution, containing 0.0001 mg. of nitrous nitrogen per cc, is the stand- 
ard to be used. [Cf. IV, 12 (d)] 

37 DETERMINATION. 

Place 5 cc. of the ether solution, A or C under 33, in a 50 cc. beaker 
dilute with 5-10 cc. of alcohol and add about 5 cc. of 0.5% alcoholic potassium hy- 
droxid. Cover with a watch glass and allow to stand 10 minutes. Place on a steam 
bath, boil, remove the watch glass and, when most of the liquid has evaporated, add 
about 25 cc. of water and return to the steam bath until about half the liquid has 
evaporated or until the odor of alcohol can no longer be detected. Cool and dilute 
with nitrite-free water to 250 cc. Each cc. of this solution represents 0.01 of a 
tablet. Introduce an aliquot, representing 0.02-0.04 mg. of nitroglycerin, into a 
100 cc. graduated flask, dilute with sufficient nitrite-free water to make the volume 
90-95 cc, add a drop of concentrated hydrochloric acid, then 2 cc. of the sulphanilic 
acid solution and 2 cc. of the alpha-naphthylamin hydrochlorid solution. Com- 
plete the volume with nitrite-free water. Prepare at the same time and in the same 
manner standards containing known amounts of sodium nitrite. Stopper the flasks, 
mix well and compare the colors after 30 minutes, using any convenient colorimeter 
or Nessler tubes. Multiply the nitrite nitrogen found by the factor 8, which has 
been determined experimentally, to obtain the equivalent of nitroglycerin. 

When 33 (a) is used for the preparation of the sample, a correction, deter- 
mined as directed above, should be made for the amount of nitroglycerin in B 
under 33, using all of B instead of an aliquot. 

Pepsin in Liquids.— tentative. 

38 REAGENTS. 

(a) Standard pepsin. — Powder a good grade of U. S. P. pepsin and pass it through 
a No. 60 sieve; dry in vacuo over calcium chlorid, again pass through a sieve and 
preserve in a stoppered bottle. Ascertain the exact pepsin equivalent of the dry 
powder by the U. S. P. method^" and express in percentage based on the assumption 
that the U. S. P. product is 100% pure. 

(b) Standard pepsin solutions. — Weigh off definite amounts of the standard pep- 
sin into the requisite quantity of N/10 hydrochloric acid to make solutions con- 
taining 5 and 0.5 mg. of pepsin per cc. These should be freshly prepared. 

(C) Ricin solution. — Grind commercial ricin, similar tb the "Ricin Prepiirat nach 
Jacoby", to a No. 60 powder, mix thoroughly, dry and keep in a desiccator. Digest 
1 gram of this powder for an hour at 37.5°C. in 100 cc. of 5% sodium chlorid solution, 
cool, filter and use at once for the assay. 

39 PREPARATION OP SOLUTIONS. 

(a) Dilute solution of the sample. — Dilute the sample with a measured amount of 
N/10 hydrochloric acid until, upon digestion at 37.5°C., 1 cc. requires approximately 
15 minutes to digest the precipitate obtained by mixing 2 cc of the ricin solution 
and 0.5 cc. of N/10 hydrochloric acid. To 50 cc. of this diluted preparation add the 
requisite quantity of water or of N/5 hydrochloric acid to make the preparation of 
N/10 acid strength when diluted with N/10 acid to 90 cc. Preserve the sample in 



364 METHODS OF ANALYSIS [Chap. 

a refrigerator. (Solid pepsin preparations may often be extracted with hydro- 
chloric acid of appropriate strength and prepared for assay in the same manner.) 

(b) Dilute comparison solution of the sample. — Add 1 cc. of N/10 hydrochloric 
acid to 9 cc. of the dilute solution of the sample. 

(C) Dilute inactive solution of the sample. — Immerse a stoppered glass vessel, con- 
taining 45 cc. of the dilute solution of the sample and 5 cc. of N/10 hydrochloric 
acid, in boiling water for 15 minutes and filter. 

(d) Standard solution containing 0.5 mg. of active U. S. P. pepsin per cc. — Im- 
merse a stoppered test tube containing 18 cc. of the dilute solution of the sample 
in boiling water for 10 minutes and, after cooling, add 2 cc. of the standard pepsin 
solution, containing 5 mg. of pepsin per cc, and filter if necessary. 

If the solutions to be tested are not clear, filter through hardened filters. If, 
however, they cannot thus be clarified, make check comparison tubes containing 
the same amounts of the preparation made up in the same way with 2 cc. of water 
in place of the ricin solution used in the determination. 



40 



DETERMINATION. 



To each of 15 tubes, add from a burette 2 cc. of the ricin solution and 0.5 cc. of 
N/10 hydrochloric acid, heat to 37.5°C. and add the following quantities of the 
solutions : 

To the first 5 tubes, add 0.00-1.00 cc. of the dilute comparison solution of the 
sample in 0.25 cc. increments, and 1.00-0.00 cc. of the dilute inactive solution of 
the sample in 0.25 cc. decrements. To the next 5 tubes, add 1.00-0.00 cc. of the 
dilute inactive solution of the sample in 0.25 cc. decrements and 0.00-1.00 cc. of the 
standard solution containing 0.5 mg. of active U. S. P. pepsin per cc. in 0.25 cc. 
increments. To the last 5 tubes, add 1.00-0.00 cc. of N/10 hydrochloric acid in 
0.25 cc. decrements and 0.00-1.00 cc. of the standard pepsin solution containing 0.5 
mg. of pepsin per cc. in 0.25 cc. increments. 

By comparing any tube of the first group of 5 with the tubes in the remaining 
groups the degree of proteolytic activity of the dilute comparison solution of the 
sample m.ay be matched against known amounts of standard pepsin both in ordi- 
nary acid medium, last group of 5, and in the same medium as the sample itself, 
second group. 

Introduce the acid and the dilute inactive solution of the sample into the tubes 
first and then pour in the solutions to be tested as rapidly as possible from gradu- 
ated pipettes, noting the total time consumed in the process after adding the pepsin. 

After the addition of the solution to be tested, again immerse the test tubes in 
the 37.5°C. bath, preferably arranged in corresponding order in a partitioned square 
or oblong wire rack, such as is used in bacteriological work. Shake and examine the 
tubes from time to time for 1-2 hours, noting the time when the digestion begins 
and ends. In case of very weak solutions they may be allowed to digest over- 
night. 

If the rate of digestion is the same in each group, the dilute comparison solution 
of the sample contains exactly 0.5 mg. of pepsin per cc. If the rate is more rapid 
in the first group than in the others, it is stronger, the comparative strength being 
closely indicated by the time of action in the tube containing less of the solution. 
If the rate of clearing is more rapid in the last group than in the second, some in- 
terfering substance is present and must be removed by dialysis, or by evaporation 
in vacuo at a low temperature until, upon re-examination and further dilution or 
concentration, the rate of digestion is identical or nearly so in each series. 

Smaller quantities of pepsin may be determined in the same way by comparing 



XXIX] DRUGS 365 

them with more dilute solutions of standard pepsin. Thus 0.05 mg. of U. S. P. 
pepsin can be readily detected by the nearly complete solvent action on the ricin 
precipitate in less than 2 hours. A marked action on the ricin within the same time 
is shown by 0.005 mg. For all practical purposes the absence of an appreciable sol- 
vent action after 4 hours digestion indicates the absence of pepsin. Express the re- 
sult in per cent, assuming U. S. P. pepsin to be 100% pure and calculating the 
result according to the dilution found necessary in preparing the dilute solution 
of the sample. 

Turpentine. 

41 color.— tentative. 

Fill a 200 cc. flat-bottomed colorimeter tube, graduated in mm., to a depth of 
40-50 mm. with the turpentine. Place the tube in a colorimeter and place on or 
under it a No. 2 yellow Lovibond glass. Over or under a second graduated tube 
in the colorimeter, place a No. 1 yellow Lovibond glass and run in the same turpen- 
tine until the color matches as nearly as possible the color in the first tube. Read 
the difference in depth of the turpentine in the 2 tubes. If this difference is 50 mm. 
or more, the turpentine is "standard". 

42 SPECIFIC GRAVITY.— TENTATIVE. 

20° C 
Determine the specific gravity at -^ — - by means of a pycnometer. The specific 

gravity may also be determined somewhat less accurately at any convenient tem- 
perature with a plummet, correcting the result by using the factor 0.00082 for each 
degree that the temperature of the determination differs from the standard tem- 
perature. 

43 REFRACTIVE INDEX. -TENTATIVE. 

Determine the refractive index at any convenient temperature with an accurate 
instrument and calculate the result to 20°C., using the correction factor 0.00045 
for each degree that the temperature of the determination differs from 20°C. 

44 DISTILLATION.— TENTATIVE. 

Use an ordinary Engler flask (the internal diameter of the side tube must be &-7 
mm.) and condenser" and heat the flask in a glycerin or oil bath^^. Fit the flask 
with a thermometer reading 145°-200°C. Place 100 cc. of the turpentine in the 
flask, connect with the condenser and distil. Conduct the distillation so that the 
distillate passes over at the rate of 2 drops per second. Note the initial distilling 
temperature and the percentage distilling below 170°C. 

POLYMERIZATION. -TENTATIVE. 

45 KEAGENT. 

S8N sulphuric acid. — Mix 140 grams of concentrated sulphuric acid with sufficient 
liquid, fuming sulphuric acid (about 10 grams) to obtain an acid slightly stronger 
than 38N. Determine the exact strength^^ of this mixture and also of the concen- 
trated acid as follows: Weigh out 6-8 grams in a bulb, having a capillary tube in the 
lower end and a tube with a stop-cock in the upper end, fitted with a platinum 
wire for suspending on a balance. (The bulb is filled by the aid of a slight vacuum, 
and the lower end of the capillary is emptied by closing the stop-cock simultaneously 
with the withdrawal of the capillary from the acid; after which it is wiped off first 
with a wet and then with a dry piece of cloth.) Run the acid into cold water, make 
up to volume and titrate an aliquot of the solution against standard alkali or add an 



366 METHODS OF ANALYSIS 

excess of ammonium hydroxid to an aliquot, evaporate to dryness, dry to constant 
weight at 120°-130°C. and weigh as ammoniimi sulphate. Calculate the sulphur 
trioxid content of the acid and add sufficient concentrated sulphuric acid to make 
it exactly 82.38% of SO3. The acid must be carefully protected against absorption 
of water from the air. 



46 



DETERMINATION. 



Place 20 cc. of the 38N sulphuric acid (100.92%) in a graduated, narrow-necked 
Babcock flask, stopper, place in ice water and cool. Add slowly 5 cc. of the turpen- 
tine. Mix the contents gradually, cool from time to time and do not allow the tem- 
perature to rise above 60°C. When the mixture no longer warms up on shaking, agi- 
tate thoroughly, place in a water bath and heat to 60°-65°C. for about 10 minutes, 
keeping the contents of the flask thoroughly mixed by vigorous shaking 5-6 times. 
Cool to room temperature and fill the flask with concentrated sulphuric acid until 
the unpolymerized oil rises into the graduated neck. Centrifugalize 4-5 minutes at 
about 1200 revolutions per minute, or allow to stand for 12 hours. Read the un- 
polymerized residue, notice its consistency and color and determine its refractive 
index. 

BIBLIOGRAPHY. 

1 U. S. Bur. Chem. Bull. 152, p. 239. 

2 .1. Ind. Eng. Chem., 1915, 7: 519. 

3 Ibid., 1914. 6:665. 

* U. S. Bur. Chem. Bull. 162, p. 197. 

5 J. Ind. Eng. Chem. 1915, 7: 681. 

«Ibid., 1912, 4:374. 

' U. S. Bur. Chem. Circ. 94, p. 4. 

«Am. J. Pharm., 1911, 83: 359. 

'Trans. Roy. Soc. Edinburgh, 1885, 32: 67. 
1" U. S. P., VIII, 1905, p. 334. 

" Stillman. Engineering Chemistry. 4th ed., 1910, p. 503. 
" U. S. Bur. Chem. Bull. 135, p. 2(5. 
» U. S. Bur. Chem. Circ. 85, p. 12. 



INDEX 

Abrastol 151 

Acetanilid 352, 356, 358, 359, 360 

and acetphenetidin, in mixtures 354 

sodium salicylate, in mixtures 357 

Acetphenetidin (phenacetin) 353, 354, 356 

and salol, in mixtures 356 

Acetyl value, of fats and oils 310 

Acidity, in cheese 296 

cream of tartar 343 

distilled liquors 243 

prepared mustard 322 

total, in coffees 333 

fruits and fruit products 178 

tanning liquors 55 

volatile, in coffees 333 

water-soluble, of feeds 119 

Acids, fixed, in tomato products 324 

vinegars 256 

wines 240 

insoluble, in fats and oils {Hehner number) 307 

mineral, free, in fruits and fruit products 179 

vinegars 258 

soluble, in fats and oils 306 

total, in beers 250 

canned vegetables 186 

tomato products 324 

vinegars 256 

wines 238 

volatile, in beers 250 

canned vegetables 186 

fruits and fruit products 178 

tomato products 324 

vinegars 256 

wines 239 

insoluble, in fats and oils {Polenske number) 308 

soluble, in fats and oils {Reichert-Meissl number) 307 

Agar agar 180 

Albrech Method for lemon and orange peel color 264 

Albumin, in milk 288 

wheat flour 188 

Alcohol, in beers 249 

confectionery 132 

distilled liquors 243 

flavoring extracts 259, 262, 266, 267, 268 

367 



368 INDEX 

Alcohol, in fruits and fruit products 177 

vinegars 253 

wines 193 

extract, in spices 318 

precipitate, in fruits and fruit products 179 

vinegars 257 

Aldehydes, in distilled liquors 244 

total, in flavoring extracts 262, 265 

Alkali, black, in irrigating water 51 

Alkalies, total, in soils 27 

Alkalinity, in industrial water 50 

Allihn's Method for dextrose 106 

Almond extract 266 

Alum, in baking powders 345 

Aluminiimi, in soils 22 

waters 43 

oxid, in plants 30 

Amaranth 158 

Ammonia, in baking powders 346 

meat and meat products 274, 281 

free and albuminoid, in waters 36, 41 

Amthor Test Modified by Lasche for caramel 248 

Anise extracts 269 

Annatto 168 

Antipyrin 354 

Arsenic, in baking powders 350 

foods 171 

mineral water 48 

oxid, total, in insecticides and fungicides 66 

water-soluble, in insecticides and fungicides 67, 68, 72 

total, in insecticides and fungicides 63, 68, 69, 71, 72 

Arsenious oxid, sodium acetate-soluble, in insecticides and fungicides 65 

total, in insecticides and fungicides 64, 66, 69, 71 

water-soluble, in insecticides and fungicides 65, 67, 72 

Ash, in baking powders 345 

beers 250 

cacao products 327 

canned vegetables 185 

coffees 331 

dairy products 287, 292, 293, 294, 296 

distilled liquors 243 

flavoring extracts 260, 264 

foods and feeding stuffs 79 

fruits and fruit products 178 

leathers 59 

meat and meat products 271, 280 

plants 29 

saccharine products 128, 133, 137 

spices and other condiments 317, 321, 323 

tea 335 

vinegars 256 



INDEX 369 

Ash, in wheat flour 187 

wines 238 

Babcock Method for fat in dairy products 289, 292, 298 

Bacteria, in tomato pulp, etc 325 

Baking powders 339-350 

Bamihl Test for gluten in wheat flour 189 

Baudoin Test for sesame oil 314 

Beef fat, in lard 314 

Beers 249-251 

Benedikt-Lewkowitsch Method for acetyl value in fats and oils 310 

Modified, for moisture in soap 73 

Benzaldehyde, in almond extract 266 

Benzoic acid 143-145 

Beta-Naphthol 151 

Blarez Method, Modified, for fluorids 149 

Borates 146 

Bordeaux mixture 69 

with lead arsenate 72 

Paris Green 71 

Boric acid 146 

in mineral water 49 

Bromin, in mineral water 47 

Butter 294 

renovated 295 

Butyric acid, in tomato products 324 

Cacao products 327-330 

Cafifein. in coffees - 332 

drugs 352, 353, 354, 359, 360 

tea 336 

and acetanilid, in mixtures 351 

acetphenetidin (phenacetin), in mixtures 353 

antipyrin, in mixtures 353 

acetanilid and codein sulphate, in mixtures 359 

quinin sulphate, in mixtures 359 

and morphin sulphate, in mixtures. . . 360 

Calcium, in mineral water 43, 50, 51 

plants 31 

soils 23 

arsenate 69 

carbonate required, in soils 28 

Canned vegetables 185-186 

Capsicum, in ginger extract 268 

Caramel, in distilled liquors 248 

Carbon, inorganic, in soils 19 

in plants 29 

organic, in soils 18 

dioxid, in insecticides and fungicides 70, 71, 72 

mineral water 42 

plant ash 29 

available, in baking powders 343 



370 INDEX 

Carbon, dioxid, residual, in baking powders 343 

total, in baking powders 339 

Carbonic and bicarbonic acids, in waters 42, 49 

Casein, in dairy products 287, 294 

milk chocolate 329 

Cassia extract 267 

Cereal foods 187-191 

Chace Method for pinene 265 

total aldehydes in flavoring extracts 262, 265 

Cheese. 296 

Chicory, in coffee 334 

Chlorin, in butter 294 

cyanids 73 

meat extracts 280 

plants 32, 33 

waters 38, 41, 49, 51 

wheat flour 189 

wines 238 

Chlorophyll 168 

Cholesterol and phytosterol, in mixtures of animal and vegetable fats 311 

Cinnamon extract 267 

Citral, in flavoring extracts 263, 265 

Citric acid, in fruits and fruit products 182 

Clarifying reagents for optical methods 82 

Clove extract 267 

Coating and glazing substances, in coffees 333 

Cochineal 168 

Codein sulphate 359 

Coffee, green 331 

roasted 331 

Coffees 331-334 

Color, in beers 249 

potable water 35 

vinegars 257 

residual, in vanilla extract 261 

value, in vanilla extract 261 

wheat flour 191 

water-insoluble, in whiskies 248 

Coloring matters 155-169 

in dairy products 292, 293, 295 

wines 240 

natural 163, 168 

separation by immiscible solvents 157 

Colors, insoluble in amyl alcohol, in distilled liquors 248 

vanilla extract 261 

Condensed milk (sweetened) 293 

(unsweetened) 293 

Condiments 317-326 

Cook Method for glycerol in meat extracts 285 

Copper, in foods 175 



INDEX 371 

Copper, in insecticides and fungicides 70, 71, 72 

carbonate 69 

oxid, total, in insecticides and fungicides 66 

reducing substances in spices and other condiments 318, 322 

Cottonseed oil 313 

Coumarin, in vanilla extract 259 

Cowles Method for malic acid value 138 

Cream 292 

of tartar in wines 240 

Creatin, in meat and meat products 275, 284 

Creatinin, in meat extracts 285 

Crude fiber, in cacao products 327 

coffees 333 

foods and feeding stuffs 118 

spices and other condiments 318, 322 

tea 336 

wheat flour 187 

Cyanids, sodium and potassium 72 

Dairy products 287-298 

Dextrin, in beers 250 

fruits and fruit products 179 

honey 134 

vinegars 25& 

wines 241 

Dextrose, in foods and feeding stuffs 106 

honey 134 

Diastase, in honey 136 

Distilled liquors 243-248 

Drugs 351-386 

Dulcin 152 

Dyes, acid 159 

basic 159 

coal tar 156 

oil-soluble 156 



Emery Method for beef fat in lard 314 

Erythrosine 158 

Esters, in distilled liquors 244 

Ether extract, in butter 294 

confectionery 131 

foods and feeding stuffs 80 

meat 271 

prepared mustard 322 

wheat flour 187 

volatile and non-volatile, in spices 318 

Extract, in beers 249 

distilled liquors 243 

wines 236 

cold water-soluble, in wheat flour 188 



372 INDEX 

Facing, in tea 337 

Fat, in cacao products 328 

coffees 334 

dairy products 289, 292, 293, 295, 297 

leathers 59 

meat extracts 280 

Fats and oils 299-315 

Fatty acids, free, in fats and oils 310 

liquid and solid, in fats and oils 309 

Feder Anilin Chlorid Test for commercial invert sugar 136 

Ferric oxid, in plants 30 

Fertilizers 1-15 

Fiehe Test {Bryan Modification) for commercial invert sugar 135 

Fincke Method for formic acid in vinegars 257 

Fish oil, in the presence of vegetable oils 315 

Flavoring extracts 259-269 

Flour, wheat 187 

Fluoborates 149 

Fluorids 149 

Fluosilicates 149 

Folin Aeration Method for ammonia in meat 274 

Food 2ireservatives 141-154 

Foods and feeding stuffs 79-119 

Formaldehyde 147-149 

solutions 75 

Formic acid 152 

in vinegars 257 

Fruit products 177-184 

Fruits 177-184 

Fimgicides 63-77 

Furfural, in distilled liquors 244 

Fusel oil, in distilled liquors 245 

Galactan, in foods and feeding stuffs 118 

Gelatin, as coating substance, in coffees 334 

dairy products 291, 293 

fruits and fruit products 180 

meat and meat products 274, 281 

Ginger, in ginger extract 268 

cold-water extract 318 

extract 267 

Glazing substances, in coffees 333 

Globulin, in wheat flour 188 

Glucose, in leathers 60 

commercial, in fruits and fruit products 179 

saccharine products 130, 135 

wines 237 

Gluten, in wheat flour 189 

Glutenin, in wheat flour 188 

Glycerol, in beers 250 

flavoring extracts 259, 262 



INDEX 373 

Glycerol, in meat extracts 285 

vinegars 253 

wines 236 

Glycogen, in meat 276 

Goldenberg-Geromont-Heidenhain Method for total tartaric acid in baking powders 343 

Gorier Method for caffein in coffee 332 

Gum, in wines 241 

Gunning Method for organic and ammoniacal nitrogen in fertilizers 7 

Modified, for total nitrogen in fertilizers 8 

Halphen Test for cottonseed oil 313 

Hanus Method for iodin absorption number of fats and oils 305 

Hardness, permanent, in industrial water 51 

temporary, in industrial water 50 

total, in industrial water 51 

Hay Method, Modified, for nitroglycerin in tablets 362 

Hedges Method, Modified, for total arsenious oxid in insecticides and fungicides 64 

Hehner Method for formaldehyde I47 

free mineral acids in vinegars 258 

number, of fats and oils 307 

Herzfeld Gravimetric Method for invert sugar 98 

Modification of the alcohol extraction method for sucrose in beets. ... 138 

Sachs le Docte Method for sucrose in beets 139 

Hess and Prescott Method, Modified, for vanillin and coumarin 259 

Hide substance, in leathers 61 

Hiltner Method for citral in flavoring extracts 263, 265 

Honey 133-136 

Hortvet Method for volatile acids in wines 239 

and West Method for oil in anise and nutmeg extracts 269 

cassia, cinnamon and clove extracts 267 

Modified, for methyl salicylate in wintergreen extract 269 
Howard Method, Modified, for oil in peppermint, spearmint and wintergreen ex- 
tracts 268 

Hiibl Method for iodin absorption number of fats and oils 304 

Hydrocyanic acid, in almond extract 266 

Hydrogen sulphid, in mineral water , 41 

Indigo carmine 158 

Insecticides 63-77 

Insoluble residue, in soils 22 

Invert sugar, in foods and feeding stuffs 85 

commercial, in honey 135 

Iodin, in mineral water 47 

absorption number of fats and oils 304 

Iron, in mineral water 43 

soils 22 

and aluminium in mineral water 42, 50 

Jorissen Method for sucrol or dulcin 152 

Test for salicylic acid 142 



374 INDEX 

Kissling Method for nicotin in tobacco and tobacco extract 73 

Kjeldahl Method for organic and ammoniacal nitrogen in fertilizers 5 

Modified, for total nitrogen in fertilizers <S 

-Gunning -Arnold Method for organic and ammoniacal nitrogen in ferti- 
lizers 7 

Kleber Method for citral in lemon and orange oils 265 

Koettstorfer number of fats and oils 306 

Lactose, in cacao products 329 

dairy products 288, 292, 293 

foods and feeding stuffs 104 

La Wall Method, Modified by Doyle, for capsicum in ginger extract 268 

Leach and Lythgoe Method for methyl alcohol in distilled liquors 247 

Method for coloring matters in milk 292 

formaldehyde 148 

Lead, in baking powders 346 

arsenate 67-69 

number, in maple products 137 

vanilla extract 260 

oxid, total, in insecticides and fungicides 67, 72 

precipitate, in vinegars 255 

Leathers 59-61 

Leffman and Beam Method for soluble volatile acids in fats and oils 308 

Lemon extracts 261 

oil 264 

in lemon extract 262 

and orange peel color 264 

Levant Wormseed 361 

Levulose, in honey 134 

Light Green S F yellowish 159 

Lime-sulphur solutions 76-77 

Lindo-Gladding Method for potash in fertilizers 12 

Lithium, in mineral water 45 

London purple 6&-67 

Low, A.H., Volumetric Method, Modified, for determining the amount of reduced 



copper. 



96 



Lowenthal Method, Proctor Modification, for tannin in tea 336 

Magnesium, in mineral water 44, 50, 51 

plants 31 

soils 23 

Malic acid, in fruits and fruit products 181 

value, in maple products 138 

Maltose, in foods and feeding stuffs 102 

Manganese, in mineral water 47 

plants 31 

soils 23 

Maple products 136- 138 

Marcusson and Schilling Method for cholesterol and phytosterol 312 

Marr Method, Modified, for inorganic carbon in soils 19 

Marsh Method, Modified, for color insoluble in amyl alcohol 248 



INDEX 375 

Mayrhofer Method, Price Modification, for starch in meat 276 

McGill Method, Modified, for starch in baking powders 345 

Meat 271 

bases in meat 274 

extracts 280 

and meat products 271-286 

Melting point determinations 301 

Metals, in foods 171-176 

Methyl alcohol, in distilled liquors 246 

flavoring extracts 261, 264 

salicylate, in wintergreen extract 269 

Micro-analysis of tomato pulp, ketchup, puree and sauce (paste) 324 

Milk 287-292 

fat, in milk chocolate 328 

Mitchell Method for lemon and orange oils 262 

Mohler test, Modified, for benzoic acid 144 

Moisture, in cacao products 327 

canned vegetables 185 

coffees 331 

dairy products 294, 296 

fertilizers 1 

foods and feeding stuffs 79 

insecticides and fungicides 63, 66, 67, 69, 71, 72 

leathers 59 

meat and meat products 271 , 280 

saccharine products 121, 133, 136 

soils 17 



spices. 



317 



tea 335 

wheat flour 187 

Molds, in tomato pu'p, etc 324 

Morphin sulphate 360 

Morpurgo Method for sucrol or dulcin 152 

Munson and Walker Method for reducing sugars 86 

Mustard, prepared 321 

Muter Method, Modified by Lane, for liquid and solid fatty acids 309 

Naphthol Yellow S 158 

Nitrates, in fertilizers 5 

meat and meat products 278, 285 

wines 241 

Nitrobenzol, in almond extract 267 

Nitrogen, in fertilizers 5-12 

leathers 61 

nitrate salts, in fertilizers 11 

non-volatile ether extract, in spices 317 

saccharine products 129 

albmninoid, in foods and feeding stuffs 80 

alcohol-soluble, in meat extracts 284 

amino, in foods and feeding stuffs 80 

meat extracts 282 



376 INDEX 

Nitrogen, amino, in wheat flour 188 

ammoniacal, in fertilizers 10 

connective tissue, in meat 273 

nitrate, in waters 37, 41, 49 

nitric and ammoniacal, in fertilizers 10 

nitrite, in waters 37, 41 

wheat flour 190 

organic and ammoniacal, in fertilizers 5 

in fertilizers 11 

soluble and insoluble, in meat 273 

total, in cacao products 327 

dairy products 287, 292, 296 

fertilizers 8-10 

meat and meat products 273, 280 

soils 21 

spices 317 

Nitroglycerin, in tablets 361 

Nontannins, in tanning materials 54, 55 

Nutmeg extracts 269 

Odor, in potable water 35 

Oil, in anise and nutmeg extracts 269 

cassia, cinnamon and clove extracts 267 

peppermint, spearmint and wintergreen extracts 268 

Oleomargarine 295 

Olive oil, in paprika 319 

Orange extract 261 

oil 264 

in orange extract 262 

1 158 

Oxygen, dissolved, in potable water 40 

required, in potable water 39 

ParaflBn, in confectionery 132 

tea 337 

Paris Green 63-66 

Peanut oil ^^^ 

Pellet Aqueous Method for sucrose in beets 139 

Pentosans, in foods and feeding stuffs HO 

vinegars 257 

wines 241 

Peppermint extract 268 

Pepsin, in liquids 363 

Peptones, in meat and meat products 274 

Petroleum ether extract, in coffees 333 

tea 335 

Phosphoric acid, in baking powders 346 

beers 250 

fertilizers 1~5, 14 

mineral water 46 

plants 31 



INDEX 



377 



Phosphoric acid, in soils 22, 24 

wines 238 

soluble and insoluble, in vinegars 256 

Phosphorus, soluble in N/5 nitric acid, in soils 27 

total, in meat and meat products 271, 280 

soils 25 

water-soluble, in meat 271 

Phytosterol, in mixtures of animal and vegetable fats 311 

Pigments ^^^ 

used in tea for coloring or facing 337 

Pinene, in lemon and orange oils 265 

Plant constituents 29-33 

Polarization, in foods and feeding stuffs 83, 84 

fruits and fruit products 1^9 

saccharine products 129, 133, 136 

vinegars '^'^'^ 

wmes ^'*' 

direct, in beers 250 

Polenske Method for insoluble volatile acids in fats and oils 308 

number, of fats and oils 308 

Ponceau 3R ■ J^^ 

Potash in fertilizers 12 14 

Potassium, in mineral water 

plants ^^ 

soils 24 

total 26 

bitartrate in baking powders 344 

Preservatives, in foods „«, 

milk 

wines 

Protein, in beers 

condensed milk ^_^ 

179 
fruits and fruit products y'^ 

prepared mustard 

t«ia »^« 

wheat flour 

alcohol-soluble, in wheat flour - 

coagulable, in meat and meat products 2/4, -81 

crude, in foods and feeding stuffs 

wines 2gi 

insoluble, in meat extracts • -^ 

Proteoses, in meat and meat products 

^ . . , , , 359, 360 

Quinin sulphate 

RaflBnose, in beet products 

Raw sugars, general directions for optical methods 

Read Method for pigments used in tea for coloring or facing ^^' 

Reducing substances, total, before inversion, in vinegars ^o^ 

sugars, in beers ec lOQ 

foods and feeding stuffs »i), luy 



291 
242 
251 
293 



378 INDEX 

Reducing sugars, in fruits and fruit products 179 

saccharine products 131, 134, 137 

wines 237 

after inversion, in tomato products 324 

vinegars 255 

before inversion, in tomato products 323 

vinegars 255 

other than dextrose, in foods and feeding stuffs 109 

Refractive index, of fats and oils 300 

lemon and orange oils 264 

Reichert-Meissl Method for soluble volatile acids in fats and oils 307 

number, of fats and oils 307 

Renard Test, Modified, for peanut oil 313 

Resin oil 313 

Riche and Bardy Method for methyl alcohol in distilled liquors 246 

Rimini Method for formaldehyde 148 

Roese-Gottlieb Method for ether extract in confectionery 131 

fat in dairy products '. 289, 293 

Saccharin 145 

Saccharine products 121-139 

Sachsse Method, Modified, for starch 110 

Salicylic acid 141-143 

Salol, in drugs 357 

Salt, in canned vegetables 185 

dairy products 294, 296 

prepared mustard 321 

Sand, in plants 29 

tomato products 323 

Sangle-Ferrihre Method for abrastol 152 

Saponification number of fats and oils {Koettstorfer number) 306 

Schlosing-Wagner Method for nitrates in meat 278 

Schmidt-Bondzynski Method, Modified, for fat in cheese 297 

Schulze-Trommsdorf Method for required oxygen in water 39 

Seeker Method for ginger in ginger extract 268 

Serum, acetic, in milk 291 

copper, in milk 291 

sour, in milk 291 

Sesame oil ^1^ 

Silica, in mineral water 42, 49 

plants 29 

Sinibaldi Method for abrastol 151 

Slag, Thomas or basic 14-15 

Smith, J. Lawrence, Method for total alkalies in soils 27 

Method, Modified, for total arsenious oxid in insecticides and fungicides . 65 

Soap 73 

Soda lye '^^ 

Sodium, in mineral water 45 

plants 32 

soils 24 

chlorid, in tomato products 323 



INDEX 379 

Sodium salicylate 358 

Soils 17-28 

Solids, in dairy products 287, 292, 293 

flavoring extracts 260, 264, 267 

fruits and fruit products 177 

leathers 61 

saccharine products 122 

spices and other condiments 321, 323 

tanning materials 53, 55 

vinegars 255 

waters 35, 41, 49, 51 

insoluble, in tomato products 323 

non-sugar, in wines 237 

soluble, in coffees 331 

Soxhlet Method for dextrose 106 

invert sugar in foods and feeding stuffs 86 

Wein Method for lactose 104 

Spdth Method for fats and waxes in coffee 334 

Spearmint extract 268 

Special tests for coal tar dyes permitted under the Federal Food and Drugs Act. 162 

Specific gravity, in beers 249 

distilled liquors 243 

fats and oils 299 

flavoring extracts 259, 261, 264 

saccharine products 122 

vinegars 253 

wines 193 

Spices 317 

microscopic examination of 319 

and added pungent materials in vinegars 258 

other condiments 317-326 

Spores, in tomato pulp, etc 325 

Stahlschmidt Method, Modified, for caffein in coffee 332 

Starch, in baking powders 344 

cacao products 328 

coffees 333 

foods and feeding stuffs 110 

fruits and fruit products 180 

meat 276 

saccharine products 131 

spices 318 

Strontium, in mineral water 44 

Sucrol 152 

Sucrose, in cacao products 329 

condensed milk 293 

flavoring extracts 260, 264 

foods and feeding stuffs 81-85 

fruits and fruit products 179 

saccharine products 129, 134, 137, 138 

tomato products 324 

wines 237 



380 INDEX 

Sugar, as a coating and glazing substance, in coffees 333 

house products 138 

Sugars, in canned vegetables 186 

cattle foods 109 

distilled liquors 246 

meat and meat products 278, 285 

wheat flour 187 

Sulphite-cellulose, in tanning materials 54 

Sulphuric acid, in baking powders 346 

mineral water 44, 50, 51 

plants 32 

soils 24 

wines 238 

Sulphur, in mustard 319 

plants 32 

Sulphurous acid 150 

Sweetening substitutes, in fruits and fruit products 184 

Tannin, in cloves and allspice 319 

leathers 61 

tanning materials 54 

tea 336 

wines 240 

Tanning extracts 53 

liquors 55 

materials 53-57 

raw and spent 56 

Tartaric acid, free, in baking powders 344 

wines 240 

or combined in baking powders 343 

total, in baking powders 343 

fruits and fruit products 180 

vinegars 257 

wines 240 

and tartrates in vinegars 257 

Tartrazine 158 

Tea 335-337 

Thomas or basic slag 14-15 

Tin, in foods 173 

Titer test for fats and oils 302 

Tobacco and tobacco extract 73-75 

Tomato products 322 

Tragacanth 360 

Trillat Method for methyl alcohol in distilled liquors 246 

Trowbridge and Francis Method for glycogen in meat 277 

Turbidity, in potable water 35 

Turmeric 168 

Turpentine 365 

Ulsch-Street Method for nitric and ammoniacal nitrogen in fertilizers 10 



INDEX 381 

Unsaponifiable residue, in fats and oils 312 

Vanilla extract and its substitutes 259 

resins 260 

Vanillin, in vanilla extract 259 

Van Slyke Method for amino nitrogen in meat extracts 282 

Villavecchia Test for sesame oil 314 

Vinegars 253-258 

Volatile matter, in soils 17 

oil, in tea 336 

Volhard Method for chlorin in plant ash 32 

Water extract, acidity of, in wheat fiour 187 

in tea 335 

industrial 49-51 

irrigating 51-52 

mineral 41-49 

potable 35-41 

Waters 35-52 

Water-soluble material, in leathers 59 

Waxes, in coffees 334 

Wein Method for maltose 103 

Wiley Method for melting point of fats and fatty acids 301 

Wines 193-242 

Winkler Method, as Modified by Drown and Hazen, for dissolved oxygen in water 40 

Rideal and Stewart, for dissolved oxygen in water 40 

Wintergreen extract 268 

Winton Method for soluble solids in coffees 331 

Ogden and Mitchell Method for nitrogen in non-volatile ether extract. . 317 
Wolff Method for free or combined tartaric acid in baking powders 343 

Yeasts and spores, in tomato pulp, etc 325 

Zinc, in foods 175 

arsenite 69 



THE END 



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